Paula Deen's Shrimp Gumbo Casserole (Adjusted)

Ingredients
Gumbo:
1 cup finely chopped onion
1 cup finely chopped celery
Heavy spary of olive oil cooking spray
1/2 teaspoon dried thyme
1 teaspoon lemon-pepper seasoning
1 tsp garlic
1 cup chicken stock
1 (14 1/2-ounce) can diced tomatoes
10-ounce package frozen cut okra
2 cups shrimp, cleaned, peeled, and deveined
2 cups of cooked brown rice

Topping:
1 egg, beaten
1/3 cup milk
12-ounce package corn muffin mix

Directions
In a skillet, spray with cooking spray and then saute onion and celery. Add thyme, lemon-pepper seasoning and garlic. Pour in stock and add tomatoes and okra. Cover pot and gently simmer for 30 minutes. Remove from heat and stir in shrimp. Transfer to a 9 x 13 glass baking dish that is coated with cooking spray.

To prepare the topping, preheat oven to 400 degrees F. Mix together egg and milk, add to muffin mix, and combine until just well-blended. Drop by tablespoonfuls on top of hot shrimp mixture, leaving the center uncovered. Bake 15 to 20 minutes.