shrimp au gratin

Ingredients

• 2 pounds raw shrimp (peeled, deveined, tail removed)
• 1 large onion, diced
• 1 medium green bell pepper, diced
• 2 cloves garlic, finely chopped
• 2 tablespoons celery, finely chopped
• 1 stick butter or margarine, halved
• 1 cup evaporated milk or whipping cream (whichever is available)
• 1 tablespoon all purpose flour
• 1 can cream of mushroom soup
• 1 large box of velveeta cheese, cut into cubes
• - tony chachere's seasoning to taste
• - garlic/onion powder to taste
• 1 - capful of zatarain's liquid seafood boil
• - pasta of choice, cooked and drained (approx 16 oz box)