4 tablespoons oil, divided (or as needed)
• ▢ 1 sweet yellow/red onion, thinly sliced (2-inch slices)
• ▢ 1/4 red bell pepper, thinly sliced
• ▢ 1/4 green bell pepper, thinly sliced
• ▢ 2½ to 3 oz petite sirloin, thinly sliced sirloin
• ▢ 1 ½ teaspoons Seasoned Salt
• ▢ 1 teaspoon minced garlic
• ▢ 2 hoagie rolls
• ▢ 2 tablespoons softened butter
• ▢ 3 ounces grater Provolone cheese/mozzarella