Deviled Crab on Toast

Name: Deviled Crab on Toast
Ingredients: 2 tablespoons butter; 2 tablespoons AP flour; 1 cup half and half; 1/2 teaspoon dry mustard powder; 2 teaspoons Worcestershire sauce; 1/2 teaspoon salt; 1/8 teaspoon white pepper; 1/8 teaspoon cayenne pepper; 1 thinly sliced green onion; 8 ounces fresh pastuerized blue crab meat (lump or backfin); 3 or 4 slices of your favorite toast; Sweet paprika for garnish