Family-Size Philly Cheesesteak Sandwich

Heat butter and oil in skillet on medium-high heat.  Add onion and peppers.  Sauté 12 minutes or until vegetables are tender.  Remove from heat and set aside.

Lay bread open-faced on baking sheet.  Place roast beef slices on bottom of loaf.  On top of loaf, evenly distribute sautéed vegetables and shredded cheese.  Bake 8 to 10 minutes or until warmed through and cheese is melted.  

Remove baking sheet from oven.  Allow to cool 2 minutes.  Place bottom half of bread on top half; hold together while flipping upright to prevent vegetables from sliding off bread.  Slice to serve.