Crawfish Etouffee (Cajun)

2 bunches scallions, chopped
1 bunch fresh parsley, chopped
4 stalks celery, sliced
1/2 bell pepper, chopped
1/4 pound butter
2 tablespoons tomato paste (or catsup)
Garlic powder, to taste
Black pepper, to taste
Salt, to taste
Red pepper, to taste
2 tablespoons flour
2 pounds peeled crawfish tails

Saute chopped vegetables in butter until onion is transparent. Add tomato paste and seasonings to taste. Stir in flour and, continuing to stir, add water gradually. Add crawfish tails and reduce heat to simmer. Cook for 15 minutes. Adjust seasonings and remove from heat.

Serve over rice.