In a food processor, lightly mince:
12 to 16 ounces of ham
6 oz. Swiss cheese, grated
2 Tbsp. chopped onion
Don't process more than three or four pulses. Don't make paste!
Add remaining ingredients, mixing by hand:
1 teas. poppy seeds
1 teas. Worcestershire sauce
2 teas. prepared mustard
4 oz. butter at room temperature
Open 1-1/2 packages of small dinner rolls, packaged flat. Cut the whole pack in half, lengthwise. Spread the ham mixture, recover the top, wrap and refrigerate until ready to heat.
Heat oven to 350 degrees. Heat rolls 10-15 minutes.