For the steaks:
(2) 10-12 oz boneless rib-eye steaks, 1½ inches thick
Sea salt and freshly ground pepper
2 Tbs. extra-virgin olive oil
3 Tablespoons chopped rosemary

For the caramelized onions & mushrooms:
2 medium sweet onions, sliced
10 oz baby portobello mushrooms, sliced
2 tablespoons extra virgin olive oil
2 tsp white balsamic vinegar