Philly Cheese Steak Sliders

Ingredients:
2 tsp. olive oil
1 medium onion, sliced
1 medium green (or red) bell pepper, sliced
8 oz. sliced mushrooms
1 Tbsp. finely chopped fresh oregano (or 1 tsp. dried oregano leaves)
Sea salt (or Himalayan salt) and ground black pepper (to taste; optional)
8 oz. raw lean beef sirloin, sliced very thin
¼ cup sliced banana (or cherry) peppers (optional)
2 oz. thinly sliced provolone cheese
4 small whole wheat rolls, split, toasted

Preparation:
1. Heat oil in large nonstick skillet (or griddle) over medium-high heat.
2. Add onion and bell pepper; cook, stirring frequently, for 3 to 5 minutes, or until onions are soft.
3. Add mushrooms and oregano. Season with salt and pepper if desired; cook, stirring frequently, for 3 to 5 minutes, or until mushrooms are soft.
4. Add sirloin; cook, stirring frequently, for 3 to 4 minutes, or until beef is cooked through.
5. Top evenly with banana peppers (if desired) and cheese. Remove from heat; cover and let stand for 1 to 2 minutes, or until cheese is melted.
6. Top buns evenly with meat mixture; serve immediately