Classic Chicken and Vegetable Casserole

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · Published 2026-04-15 · Updated 2026-04-15

A one-dish wonder with tender chicken and mixed vegetables baked in a creamy sauce, perfect for weeknight dinners. This american-inspired one pot ready in about 60 minutes pairs olive oil, medium, diced onion, diced carrots for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 350 calories and feeds 6, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" 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

• 1.5 lbs, boneless and skinless, cut into 1-inch pieces chicken thighs
• 2 tbsp olive oil
• 1 medium, diced onion
• 2, diced carrots
• 2 stalks, diced celery
• 1/2 cup all-purpose flour
• 2 cups chicken broth
• 1 cup milk
• 1/2 cup sour cream
• 1 tsp dried parsley
• 1/2 tsp dried thyme
• 1/4 tsp salt
• 1/8 tsp black pepper
• 1.5 cups frozen mixed vegetables
• 1/2 cup breadcrumbs
• 1 tbsp melted butter

Instructions

1. Step 1: Preheat oven to 375°F (190°C). Heat 2 tbsp olive oil in a large skillet over medium-high heat, then add 1.5 lbs chicken thighs (cut into 1-inch pieces) and cook for 8-10 minutes until browned on all sides, turning occasionally.
2. Step 2: Add 1 medium onion (diced), 2 carrots (diced), and 2 stalks celery (diced) to the skillet, cooking for 5 minutes until softened. Stir in 1/2 cup all-purpose flour and cook for 1 minute, then gradually whisk in 2 cups chicken broth and 1 cup milk until smooth.
3. Step 3: Bring to a simmer and cook for 3 minutes until thickened, then stir in 1/2 cup sour cream, 1 tsp dried parsley, 1/2 tsp dried thyme, 1/4 tsp salt, and 1/8 tsp black pepper. Remove from heat, add 1.5 cups frozen mixed vegetables, and transfer to a greased 9x13-inch baking dish. Top with 1/2 cup breadcrumbs mixed with 1 tbsp melted butter.