Melt butter in large heavy frying pan. Add onion, garlic, peppers and cook over low heat for 2 - 3 minutes. Add flour and stir until it is well incorporated. Continue to cook 2 - 3 minutes more but do not allow to brown. Gradually add cream and stir until thickened.
Add dry mustard, prepared mustard, herbs, cayenne pepper and tabasco. Mix well. Stir in egg yolk and quickly add crab meat, lemon juice and bread crumbs. Stirring until well blended. Remove from heat. Season with salt and pepper to taste.