Creamy Chicken & Yellow Squash Gratin with Tomato Breadcrumb Topping

Instructions

1. 1

   Preheat the oven to 400°F (200°C). Lightly grease a 9x9-inch or similar baking dish — this will cradle everything snugly.

2. 2

   Season the chicken pieces with salt, pepper, and the thyme. In a large skillet over medium-high heat, warm 1 tbsp olive oil. Sear the chicken in batches until lightly browned but not fully cooked through, about 2 minutes per side. Transfer chicken to a plate — it will finish cooking in the oven.

3. 3

   In the same skillet, add the remaining 1 tbsp olive oil. Sauté the sliced onion until translucent, about 4 minutes. Add the garlic and cook 30 seconds until fragrant.

4. 4

   Add the sliced yellow squash and cook, stirring occasionally, until just beginning to soften, about 4 minutes. Stir in the diced tomatoes and cook 1–2 minutes to release some juices.

5. 5

   Pour in the cream and chicken broth, scraping up any browned bits — that’s flavor, dear. Bring the mixture to a gentle simmer, then stir in 1/4 cup of the Parmesan and 1/2 cup of the shredded cheese. Taste and adjust seasoning with salt and pepper.

6. 6

   Return the seared chicken to the pan, folding gently so pieces are coated with the sauce. Let everything come together for a minute, then transfer the mixture into the prepared baking dish, spreading evenly.

7. 7

   In a small bowl, combine the breadcrumbs, melted butter, remaining 1/4 cup Parmesan, and remaining 1/2 cup shredded cheese. Stir in the chopped tomatoes (if you like a fresher tomato pop in the topping) or reserve the tomatoes for beneath — either way adds charm.

8. 8

   Sprinkle the breadcrumb mixture evenly over the casserole. This will make a beautifully golden crust.

9. 9

   Bake for 20–25 minutes, until bubbling and the top is golden brown and the chicken reaches 165°F (74°C). If the topping browns too fast, tent loosely with foil.

10. 10

    Let rest 5 minutes before serving — it makes cutting neater and the flavors settle. Sprinkle with chopped parsley or basil for a cheery finish.