Beef Stew with cremini

2 lbs beef flat iron steaks 1 tablespoon butter 2 tablespoons olive oil salt pepper 1 cup finely chopped onion 1 tablespoon finely chopped garlic 1 tablespoon[...]

1 1/2 lbs stewing beef (cut into 1-inch bite size pieces) 2 cups cremini mushrooms (cut in half depending on the size) 2 large onions , cut in half and thin[...]