Quick Shrimp Creole

I've made this dish once a week for several weeks now, and I've reduced my time to about 35 minutes start to finish. It's delicious and comfort-food-like while still being light. It's also super fast, since I use the chopped bell peppers and onions in Trader Joe's freezer section, canned diced tomatoes, and frozen shrimp.

INGREDIENTS

1 stick butter
1 cup chopped bell pepper (or 1/2 the bag of chopped bell pepper and onion from TJ)
1 cup chopped celery (or 1/2 the canister of "Mirepoix", aka chopped celery, onion, and carrot from TJ; it's ok if you get some carrots in there. Won't hurt anything.)
2 cups chopped onions (You already got these from the TJ bags/canisters above)

2 bay leaves
14.5-ounce can diced tomatoes
1 tablespoon chopped garlic
1 teaspoon Worcestershire Sauce
1 teaspoon hot sauce,or to taste
2 tablespoons all-purpose flour
1 cup water
1 tsp Thai fish sauce
2 1/2 pounds peeled and deveined large shrimp
1/2 cup chopped green onions
Lemon juice
2 tablespoons chopped parsley or cilantro
4 cups cooked long-grain white rice

Seasonings: I use a combo of these, and season with about 1 tsp each, then more to taste:
cayenne
paprika
salt
garlic powder
black pepper
onion powder
oregano
thyme
cumin

INSTRUCTIONS

Thaw the shrimp in a bowl of cool water while you get everything else ready. The dark nerve on the ventral side of the shrimp isn't the "vein". You can eat that nerve, so on deveined shrimp you have nothing to remove. I like using the small shrimp without tails, but the medium-large ones are good, too; just take the tails off. Season the shrimp heavily with the spices above after they are thawed and let them sit in the seasoning as you prep the sauce/roux. Don't taste or add any seasonings until after the seasoned shrimp are added and cooked. They change the flavor a LOT.

In a large sauce pan, over medium heat, melt the butter. Add the onions, peppers, and celery to the pan. Saute the vegetables until they are wilted, about 6 to 8 minutes. Stir in the bay leaves, tomatoes, and garlic. Bring the mixture to a boil and reduce to a simmer; continue to cook for 15 minutes.

In a small bowl whisk the flour and water together and add the mixture to the tomatoes. Cook for 4 to 5 minutes. Add the fish sauce, Worcestershire and hot sauce and continue to cook for 5 minutes longer. Add the seasoned shrimp. Leave it on low heat for 5 minutes and then turn the heat off. The shrimp are delicate and will cook fast.

Stir in the green onions and parsley or cilantro, and squeeze lemon juice over it.

Serve with white rice.