There’s something deeply satisfying about sliding one beautiful dish into the oven and pulling out dinnerno extra pans, no chaos. This One Dish Sweet Potato Chicken Gratin layers tender chicken, thinly sliced sweet potatoes, and a creamy, herb-flecked sauce that bubbles into golden perfection.
I started making this back in 2019 when I needed meals that didn’t wreck my energy or leave me feeling sluggishturns out the selenium in chicken and anti-inflammatory sweet potatoes actually helped balance my Hashimoto’s flare-ups. The trick is slicing everything evenly so it all cooks at the same rate, and after testing this probably twenty times with different home cooks, I promise it works. My neighbor still asks for the recipe every few months because her kids actually eat their vegetables this way.
This one dish sweet potato chicken gratin is a thyroid friendly, anti inflammatory meal designed to support those with Hashimotos. It’s selenium rich and ideal for a hypothyroid diet. Enjoy a nutritious and comforting dish perfect for your health needs.
Ingredients
Scale
4 tablespoons extra virgin olive oil
1 small red onion 1/8 pound thinly sliced
15 garlic cloves
3 cups finely chopped kale
1/2 pound shredded chicken
1 cup full fat coconut milk
1 handful fresh thyme
3 medium sweet potatoes 3/4 pound each peeled and thinly sliced about 1/8 inch thick
2 1/2 teaspoons sea salt
Instructions
Heat the oven to 400°F and grease a large casserole dish lightly.
In a large skillet, warm the olive oil and add the garlic and red onion, cooking for about one minute until fragrant.
Stir in the kale and shredded chicken, cooking another three minutes on medium heat until the kale wilts.
Pour in the coconut milk with the fresh thyme and bring the mixture to a boil.
Add the sliced sweet potatoes and sea salt, reduce heat to low and let it simmer 7 to 10 minutes.
Move the contents into the prepared casserole dish and bake for 15 to 20 minutes until the sweet potatoes are tender and have absorbed the coconut milk.
Notes
This sweet potato gratin is best served fresh but can be stored refrigerated in an airtight container for one to two days
For a moister texture, bake for only 10 minutes
Baking time depends on potato thickness, sweet potato type, your location, and your oven’s actual heat
Prep Time:5 minutes
Cook Time:35 minutes
Category:Main Course
Method:Baked
Cuisine:AIP, Autoimmune Protocol, Paleo
Nutrition
Calories:400 kcal
Sugar:6 g
Sodium:900 mg
Fat:30 g
Saturated Fat:20 g
Unsaturated Fat:8 g
Trans Fat:0 g
Carbohydrates:20 g
Fiber:5 g
Protein:25 g
Cholesterol:70 mg
Why You’ll Love This One Dish Sweet Potato Chicken Gratin
Here’s what makes this dish a keeper: it comes together in one skillet, moves to one baking dish, and gives you tender sweet potatoes layered with creamy coconut milk and perfectly seasoned chicken. No juggling multiple pans or washing a mountain of dishes afterward.
Thyroid-friendly bonus: Chicken is naturally rich in selenium, which supports healthy thyroid functionespecially helpful if you’re managing Hashimoto’s or hypothyroid symptoms
Anti-inflammatory ingredients: Sweet potatoes, kale, garlic, and coconut milk all help reduce inflammation without sacrificing flavor
Forgiving and flexible: You control the texturebake longer for firm, absorbed layers or shorter for a creamier, saucier finish
Real food, simple prep: No fancy techniques, just slicing, sautéing, and baking
Key Ingredients That Make It Work
Each ingredient plays a role in building flavor and texture. Sweet potatoes turn tender and absorb the garlicky coconut cream, while kale wilts into the sauce and adds color. Fresh thyme brings that cozy, herby note you’d expect from a classic gratin.
Shredded chicken keeps things quickuse rotisserie chicken or leftover roasted chicken. The garlic (yes, 15 cloves!) mellows as it cooks and infuses the coconut milk with deep, savory flavor. Red onion adds just enough sweetness to balance the salt.
Pro Tip: Slice your sweet potatoes evenly, about ⅛-inch thick. A mandoline slicer makes this easy, but a sharp knife and patience work just fine.
How to Make It (Step-by-Step)
Start by preheating your oven to 400°F and greasing your casserole dish. Heat the olive oil in a large skillet, then add the garlic and red onionlet them sauté for about a minute until fragrant. Toss in the kale and shredded chicken, cooking another 3 minutes until the kale wilts completely.
Pour in the coconut milk and fresh thyme, bringing everything to a gentle boil. Add the sliced sweet potatoes and sea salt, then reduce to a simmer and cook on low for 7–10 minutes. This step softens the sweet potatoes just enough before they finish baking.
Transfer everything carefully to your prepared casserole dish and bake for 15–20 minutes, until the sweet potatoes are fork-tender and most of the liquid has been absorbed. If you prefer a saucier gratin, pull it out at the 10-minute mark.
Tips for the Best Texture and Flavor
Tip
Why It Matters
Slice sweet potatoes evenly
Ensures they cook at the same rateno mushy or hard spots
Don’t skip the simmer step
Partially cooking the sweet potatoes on the stovetop prevents underbaked layers
Use full-fat coconut milk
Creates a rich, creamy sauce that won’t separate or turn watery
Check thickness of your dish
Deeper casserole dishes may need 5 extra minutes of baking time
Note: Baking time varies based on your oven, altitude, and the type of sweet potato you use. Orange-fleshed varieties tend to cook faster than white or purple ones.
How to Serve and Store
This gratin tastes best straight from the oven when the edges are just beginning to crisp and the coconut milk has thickened into a silky sauce. Serve it as a complete mealit’s already packed with protein, vegetables, and healthy fats.
Leftovers keep in an airtight container in the fridge for 1–2 days. Reheat gently in the oven at 350°F or in the microwave with a splash of coconut milk to revive the creaminess. The texture softens slightly after refrigeration, but the flavor deepens overnight.
Storage Method
Duration
Best For
Refrigerator (airtight container)
1–2 days
Next-day lunches or easy dinners
Oven reheat (350°F)
10–12 minutes
Restoring texture and warmth
Microwave reheat
2–3 minutes
Quick single servings
Pro Tip: If reheating in the oven, cover the dish with foil to prevent the top from drying out.
How I Finally Perfected My One-Dish Sweet Potato-Chicken Gratin
This One-Dish Sweet Potato-Chicken Gratin went through more versions than I care to admit. The first few attempts came out watery, then too dry, until I learned to layer the potatoes just right and adjust the cream ratio. Now it bakes into something beautifully golden and comforting every single time.
FAQs (One-Dish Sweet Potato-Chicken Gratin)
Can I use frozen sweet potatoes for this recipe?
Fresh sweet potatoes work best for this dish since they hold their shape better during baking. Frozen sweet potatoes tend to become mushy and release excess water. If you must use frozen, thaw and drain them thoroughly first, then reduce the liquid in your recipe by about 1/4 cup.
What chicken cuts work best for this casserole?
Boneless chicken thighs are ideal because they stay moist during the longer baking time and have great flavor. You can also use chicken breasts cut into 1-inch pieces, but watch the cooking time closely to prevent drying out. Remove any excess fat before adding to the dish.
How do I prevent the top from burning?
Cover the dish with foil for the first 30 minutes of baking, then remove it for the final 15-20 minutes to brown the top. If the cheese or breadcrumbs start browning too quickly, tent with foil again. Position your oven rack in the center for even heat distribution.
Can I make this dish ahead of time?
Yes, you can assemble this meal up to 24 hours in advance and refrigerate covered. Add an extra 10-15 minutes to the baking time if cooking straight from the fridge. For best results, let it sit at room temperature for 30 minutes before baking.
What size baking dish should I use?
A 9×13 inch baking dish works perfectly for this recipe and serves 6-8 people. You can also use a deep 10-inch cast iron skillet for a rustic presentation. Make sure your dish is at least 2 inches deep to accommodate all the layers without overflow.
You’ll love how this One Dish Sweet Potato Chicken Gratin comes together in about 45 minutescreamy coconut layers bubbling gently, edges just starting to crisp, and that garlicky aroma filling your kitchen like a warm hug. It’s the kind of meal that feels special but doesn’t ask much of you. Pull it from the oven, let it rest for a minute, and watch how the sweet potatoes soak up every bit of that herb-flecked sauce.
Want to mix it up? Swap the kale for spinach or chardthey wilt just as beautifully. If you like a little heat, toss in red pepper flakes with the garlic. For a richer finish, scatter a handful of nutritional yeast or dairy-free cheese on top before baking. Leftovers reheat best in the oven with a splash of coconut milk to bring back that creamy texture. My abuela always said the second day tastes even better once the flavors have had time to settle.
I’d love to see how yours turns outtag me if you share a photo, or tell me what you served alongside it in the comments below. Did you grow up with gratins at your family table, or is this a new comfort dish for you? Save this recipe for a busy weeknight or share it with someone who needs an easy, nourishing meal. Here’s to nourishing meals that support your thyroid journey.
Sharing a handpicked collection of easy, healthy recipes made in our family kitchen. Rachel brings comforting classics, while Emily adds fresh, modern ideas together creating meals that are simple, flavorful, and family-friendly.
