Pork Tenderloin with Caramelized Onions

2 large sweet onions, thinly sliced

2 lb. pork tenderloin (I use the kind with 2 in a pack)

salt and pepper

2 Tbsp butter

2 Tbsp sugar

Preheat oven to 350 degrees.   Lightly grease 1 9x13 glass baking dish.   Lay tenderloin in dish and generously salt and pepper.  Put onion slices in large microwave bowl with butter and sugar.  Microwave onions for 10 minutes, stirring after the first 5 minutes.  Once the onions are cooked, spoon them over the tenderloin.   Bake for 45 to 50 minutes or until no longer pink in center (you can put a meat thermometer in the center if you have one.... it should register 160 degrees).