Slow Cooker Cheese Steaks

Ingredients (10)

• + 2 pounds beef tri tip steak add to pantry
• + 1 cup beef stock add to pantry
• + 1 tablespoon red wine vinegar add to pantry
• + 1 tablespoon Worcestershire sauce add to pantry
• + 2 teaspoons olive oil add to pantry
• + 1 large onion, sliced add to pantry
• + 1 large green pepper, sliced add to pantry
• + 8 ounces sliced fresh mushrooms add to pantry
• + 12 slices white American cheese add to pantry
• ✓ 6 French or Italian sandwich rolls, split