One-Pot Mushroom and Thyme Chicken Casserole

By AislePrompt Editorial · Published 2026-04-24 · Updated 2026-04-24

A comforting one-pan meal with chicken breast, mushrooms, and a savory herb sauce, baked until bubbly and golden. This American one-pot recipe, ready in about 55 minutes, pairs chicken breasts, butter, and onion for a weeknight-friendly dinner. Each serving lands at about 500 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Build a week of meals around this recipe" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 4 boneless chicken breasts, skinless (about 1.5 lbs)
• 2 tbsp butter
• 1 medium onion, diced
• 8 oz cremini mushrooms, sliced
• 2 cloves garlic, minced
• 1 tbsp fresh thyme, leaves only
• 1/2 cup chicken broth
• 1/4 cup all-purpose flour
• 1/2 cup milk
• 1/4 tsp salt
• 1/4 tsp black pepper
• 1 cup cooked rice
• 1/4 cup cheddar cheese, grated

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Instructions

1. Step 1: Preheat oven to 375°F (190°C). Season chicken breasts with 1/4 tsp salt and 1/4 tsp black pepper.
2. Step 2: Melt 2 tbsp butter in a large ovenproof skillet over medium-high heat. Add chicken and cook for 5-6 minutes per side until golden brown and internal temperature reaches 165°F (74°C). Remove chicken and set aside.
3. Step 3: Add diced onion and sliced mushrooms to the skillet. Cook for 5-6 minutes until onions are translucent and mushrooms release moisture.
4. Step 4: Stir in minced garlic and 1 tbsp fresh thyme, cooking for 1 minute until fragrant. Sprinkle 1/4 cup all-purpose flour over vegetables and stir to form a paste.
5. Step 5: Gradually whisk in 1/2 cup chicken broth and 1/2 cup milk, then add 1/4 tsp salt and 1/4 tsp black pepper. Cook for 3-4 minutes until sauce thickens and coats the back of a spoon.
6. Step 6: Add 1 cup cooked rice to the skillet and stir to combine. Return chicken breasts to the skillet, nestling them into the rice and sauce. Sprinkle 1/4 cup grated cheddar cheese on top.
7. Step 7: Bake for 15-20 minutes until cheese is melted and bubbly and chicken is heated through.