Philly Cheesesteak Bread is an easy appetizer recipe inspired by the traditional Philly Cheesesteak Sandwich. This beefy, cheesy pizza bread disappears quickly, but it's a snap to make.
Heat a cast-iron skillet on mid-high heat and season the steak with 1/4 teaspoon kosher salt, and 1/8 teaspoon freshly cracked black pepper on both sides (or to your desired taste).
Place the steak in the hot, dry skillet and allow to sear for 3 minutes, without moving. You want to get a nice caramelized crust on the outside of the steak.
When the steak has a nice sear on the one side, use tongs and turn the steak over. Add 1 tablespoon of butter to the pan and sear the steak for 2-3 more minutes (or until your desired temperature) while basting with the butter. Don't move the steak, just spoon butter over the top while it sears. Remove from the skillet to a cutting board and allow to rest while preparing the vegetables.
Reduce heat to medium and melt 2 tablespoons butter in the skillet. Add 1 cup sliced onion, 1 cup sliced green pepper, and 1 cup sliced mushrooms. Salt and pepper the vegetables to your liking. Saute vegetables until tender, about 5-7 minutes.
While the vegetables are sauteing, combine 1/2 lb white American cheese cubes, 1/4 teaspoon minced garlic, 1 tablespoon, and a pinch of salt in a microwave safe bowl. Microwave for 1 minute on high, stir, and continue to microwave on high for 1 minute at a time, stirring in between each heating, until cheese is melted into a nice sauce. Thin the sauce with milk to your desired consistency.
Slice partway through the baguette at 2" intervals to make it easier to pull apart when serving.
Slice the steak into thin, bite sized pieces.
Assemble the Philly Cheesesteak Bread: Spread 1/2 the cheese sauce on each baguette and top each with 1/2 the vegetable mixer and 1/2 the steak pieces. Sprinkle 2 tablespoons mozzarella cheese onto each baguette.
Place baguettes onto a baking sheet and place under the broiler until cheese melts and bread is toasted lightly.