Philly-style Cheesy Steak Sandwiches

Ingredients

• 2 whole-grain Italian rolls, halved lengthwise
• 1 tablespoon all-purpose flour
• ½ teaspoon black pepper, divided
• 2 tablespoons olive oil, divided
• ½ cup cold 2% milk
• 1 medium size onion, thinly sliced
• 1 green bell pepper, thinly sliced
• 1 red bell pepper, thinly sliced
• ¾ teaspoon salt, divided
• 2 ounces extra-sharp cheddar cheese, finely shredded
• 1 pound boneless top loin steak, thinly sliced from being semi-frozen