Put 1/2 cup butter in a large pot, then add the onions & brown slightly. Add the tomato sauce & the whole mashed tomatoes and let simmer for 30 minutes.
Add the chicken broth, salt, & pepper and simmer for a further 30 minutes.
Bring the mixture up to a boil and add the rice, shrimp, and oysters. Reduce heat at once to very low, cover the pot, and cook for 20 minutes without removing lid. Remove lid, stir well, & cook for 10 minutes.
Place 1/2 cup butter in a skillet and burn until BLACK. Pour burned butter into the large pot with the other ingredients, stir again, and serve.