Combine crab, celery, and onion in medium sized bowl. Add mayonnaise gradually until desired consistency. Add horseradish to taste. Add Mrs. Dash food seasonings.

Melt butter in skillet one T at a time. Sauté mushroom caps (both sides) until lightly yellow-brown. Place sautéed mushrooms on a paper towel to soak up extra butter.

Fill mushroom caps with crab stuffing. Place on lightly greased baking sheet. Bake for approximately 10-15 minutes at 350°. Mushrooms and filling should be very warm to the touch, but not too hot. Serve immediately.