Philly Cheesesteaks

INGREDIENTS

• Four 5-inch sub rolls, split
• 1 tablespoon all-purpose flour
• Kosher salt and freshly ground black pepper
• 1 pound top round London broil
• 2 green peppers, cut into strips
• 2 medium onions, sliced
• 3 tablespoons canola oil
• 1/4 teaspoon cayenne pepper
• 1 cup shredded provolone
• 1 cup whole milk, warm