Short Ribs in Beer

From my family in Spain comes this recipe for short ribs and while it needs few ingredients it does take watching to insure a smooth finish.... lovely

Short Ribs in Beer.-

1 1/2K Short Ribs

1 K White onions, finely cut slices

2 tbl butter

1 tsp salt

2 - 12oz bottles dark beer

1 tbl balsamic vinegar

Preheat oven to 300 F/150 C. In large fry pan over med heat melt butter. Add onions and salt and allow to caramelize for about 20 min, moving now and then and insuring they don't burn. BUT don't move too much or they won't caramelize, they will turn a dark color like milk with chocolate and once this occurs add the beer, vinegar and put it into an baking dish along with the short ribs. Cover the ribs with aluminum foil and bake for about 3 hours or until the meat is so tender it will come off the bone with ease. Take out of the oven at this time and let rest. Set the short ribs aside. With a hand blender (or whatever you use and have) mix the onion and liquids and use this to spoon over ribs.