Philly Cheesesteak Flatbread

Ingredients

• 1 Sweet red bell pepper
• 1 Sweet green bell pepper
• 1 Small onion
• 2 Tbsp(s) Olive Oil
• 8 Sirloin Steak
• 1/4 cup Dijon mustard
• 1/4 cup Balsamic vinegar
• 1/4 cup Olive Oil
• 2 Garlic cloves
• Salt & pepper
• 8 Slices White American cheese
• 1 Flat bread pizza crust