Preheat the oven to 350°F (175°C).
In a medium saucepan, bring 2 cups of water to a boil. Add Knorr Rice Sides – Chicken flavor and cook according to package instructions (usually about 10 minutes). Set aside.
While the rice cooks, heat olive oil in a large skillet over medium heat.
Add chopped onion and cook for 3-4 minutes until translucent.
Add minced garlic and cook for 1 minute until fragrant.
Add the chicken pieces to the skillet and cook until no longer pink in the center, about 6-8 minutes. Season with salt, black pepper, paprika, and dried thyme while cooking.
In a large mixing bowl, combine the cooked Knorr rice, cooked chicken mixture, sour cream, milk, and half of the shredded cheddar cheese. Mix well until evenly combined.
Transfer the mixture into a greased 9×13 inch casserole dish.
Sprinkle the remaining cheddar cheese and mozzarella cheese evenly over the top.
Bake uncovered in the preheated oven for 25-30 minutes, or until the casserole is bubbly and the cheese on top is melted and golden brown.
Remove from the oven and let it rest for 5 minutes before serving.