- Melt butter in a large pot over medium high heat. Add the onion and cook 2-3 minutes or until aromatic.
- Add potatoes, Old Bay(R) seasoning, mustard, and thyme. Reduce heat to low and cook, stirring often, until the potatoes are just tender, about 15-20 minutes.
- Remove from the heat and stir in the flour, cayenne, salt and pepper. Mix well. Return to medium heat and stir constantly for 1-2 minutes to cook the flour. Remove from heat again and slowly pour in the LACTAID® Reduced Fat Milk, while stirring constantly to prevent lumps. Return to heat and cook over medium-low heat, stirring frequently until thickened, about 5-6 minutes.
- Add the crabmeat and parsley. Simmer over low heat 5-8 minutes or until heated through.
- Stir in sherry, if desired, and top with chopped scallions just before serving.