Chicken and Rice Casserole with Mushrooms and Thyme

Chef’s Secret: I stumbled on this casserole while trying to quietly one-up a restaurant chicken-and-rice I loved—don’t tell them. I’ll let you in on the tiny trick that makes the top turn golden and the interior stay gloriously creamy: a quick roux and a short sauté before the oven. You’ll hear a satisfying sizzle when the mushrooms hit the pan, smell thyme blossom with butter, and end up with something that tastes like it took all afternoon, even when you pull it together in under an hour.

Quick Facts

• Yield: Serves 4–6
• Prep Time: 20 minutes
• Cook Time: 45 minutes
• Total Time: 65 minutes

Why This Recipe is Awesome

This casserole feels like a warm hug: earthy **mushrooms**, tender **chicken**, and fluffy baked **rice** sitting in a silky, herby sauce. It browns on top, stays creamy inside, and smells like comfort with a little kitchen swagger— thyme and butter for the win. It’s easy enough for a weeknight, hearty enough for guests, and forgiving when you get distracted by the timer.

Ingredients

For the Main Dish:

• 1 lb boneless, skinless chicken breasts or thighs, cut into 1-inch pieces
• 1 1/2 cups long-grain white rice, uncooked
• 8 oz cremini or white mushrooms, sliced (about 2 cups)
• 1 small yellow onion, finely chopped (about 1 cup)
• 2 cloves garlic, minced
• 3 cups low-sodium chicken broth
• 1 cup milk (whole or 2% for creaminess)
• 2 tbsp unsalted butter
• 2 tbsp olive oil
• 2 tbsp all-purpose flour
• 1 tbsp fresh thyme leaves (or 1 tsp dried thyme)
• 1 cup frozen peas (optional, for color and sweetness)
• 1/2 cup grated Parmesan or sharp cheddar (optional)
• Salt and pepper to taste (about 1 tsp salt)

For the Sauce / Garnish (if applicable):

• 2 tbsp breadcrumbs mixed with 1 tbsp melted butter (optional crisp topping)
• Fresh parsley or extra thyme leaves to garnish
• Lemon zest (optional, brightens the dish)

How I Make It

Step 1:

Preheat the oven to 375°F. Pat the chicken dry and season with salt and pepper. Heat a large skillet over medium-high heat with 1 tbsp olive oil. When it shimmers, add the chicken in a single layer and brown for about 2–3 minutes per side until you get a little color—don’t cook through. Transfer the chicken to a plate; you want those browned bits left in the pan for flavor.

Step 2:

Reduce heat to medium, add the remaining 1 tbsp olive oil and 2 tbsp butter. Toss in the chopped onion and sauté until soft and translucent, about 4 minutes. Add the garlic and mushrooms and cook until the mushrooms release their juices and those juices caramelize a bit—listen for a steady sizzle and watch for rich brown edges. Sprinkle 2 tbsp flour over the veggies and stir for a minute to form a light roux.

Step 3:

Slowly pour in the 3 cups chicken broth while stirring, then add the 1 cup milk. Scrape the browned bits from the pan; those are concentrated flavor. Stir in the uncooked 1 1/2 cups rice, fresh thyme, and frozen peas if using. Taste and adjust salt and pepper. The mixture will look liquidy—that’s right. It thickens as it bakes.

Step 4:

Return the browned chicken to the skillet (nestle it into the rice) and sprinkle the top with 1/2 cup cheese if you like. Transfer everything to a greased 9×13-inch casserole dish or keep it in an ovenproof skillet. Bake uncovered at 375°F for 35–40 minutes until the rice looks tender, the top turns golden, and the edges bubble. A little crisp on top gives a lovely contrast to the creamy center.

Step 5:

Remove from the oven and let rest for 10 minutes so the casserole sets. Sprinkle with fresh parsley or extra thyme and the buttery breadcrumb topping if you crave crunch. Spoon out generous portions—each scoop should reveal tender chicken, creamy rice, and mushroom ribbons. Serve warm.

Pro Tips

• Brown the chicken in batches to avoid steaming. Those browned bits add big flavor.
• If you use brown rice, increase the broth by 1 cup and bake for an extra 20–25 minutes, or cook the rice separately and fold in near the end.
• For a richer dish, swap 1/2 cup of milk for heavy cream. For lighter, use all milk or unsweetened almond milk.
• Use fresh thyme when possible—its bright, lemony aroma lifts the whole casserole. If only dried, use about one-third the amount.

Common Mistakes to Avoid

• Skipping preheating: Classic rookie move. It changes texture and bake time.
• Overmixing: Leads to dense or chewy results. Mix until just combined.
• Guessing cook time: Always use visual cues or a timer, not just vibes.
• Overcrowding pans: Give your food some breathing room to crisp properly.

Alternatives & Substitutions

• Chicken ↔ firm tofu or chickpeas for a vegetarian version (tofu keeps texture, chickpeas add heartiness).
• Heavy cream ↔ Greek yogurt for tangy creaminess (stir yogurt in off heat to avoid curdling).
• Gluten-free: use gluten-free flour or cornstarch (1 tbsp cornstarch + 1 tbsp cold water) for the roux and gluten-free breadcrumbs.
• Dairy-free: swap butter for olive oil and milk for unsweetened oat or almond milk; reduce salt slightly to compensate for the missing flavor from butter.

Variations & Tips

• Spicy: add 1/2 tsp smoked paprika and a pinch of cayenne, or toss in sliced chorizo with the chicken.
• Kid-friendly: leave out thyme and swap mushrooms for sweet corn or diced carrots.
• Herb-forward: fold in chopped tarragon or rosemary with the thyme for a fragrant twist.
• Mushroom-forward: use a wild mushroom mix like shiitake and oyster for a deeper umami hit.
• One-pan shortcut: cook everything in an ovenproof skillet from start to finish to save dishes.
• Creamy-toasted twist: once baked, broil for 2–3 minutes to toast breadcrumbs or cheese—watch closely.

FAQ (Frequently Asked Questions)

Can I make this ahead of time?

Yes! Assemble the casserole up to step 4, cover, and refrigerate for up to 24 hours. Add 10–15 minutes to the baking time if chilled. For best texture, let it sit at room temperature for 20 minutes before baking.

Can I double the recipe?

Sure thing. Use a larger casserole (like 11×15) and expect a 10–20 minute increase in bake time. Check the rice for tenderness.

Can I substitute butter with oil?

Technically yes, but you’ll miss that buttery magic. Use ¾ the amount of oil.

How do I know it’s done?

Look for tender rice, bubbling edges, and a golden top. The chicken should reach 165°F internal temperature when measured with a thermometer.

What if I don’t have ingredient X?

Swap mushrooms for zucchini or bell pepper for similar texture. No thyme? Use parsley and a squeeze of lemon for brightness.

How I Like to Serve It

I plate this straight from the dish with a green salad and a crisp glass of white wine for a cozy Friday night. It works beautifully for potlucks—everyone queues up for seconds. In summer I add lemon zest and a cucumber salad; in winter, I pair it with roasted root vegetables for extra comfort.

Notes

• Store leftovers covered in the fridge for up to 3 days. Reheat gently in the oven at 350°F until warmed through, or microwave in 1-minute bursts.
• Cook chicken to a safe internal temp of 165°F. If you used thighs, they stay juicier; breasts dry faster.

Final Thoughts

Closing: Now go impress someone — or just yourself — with your homemade masterpiece! Trust me: the smell alone will make the whole house sit up and take notice.