Step 1

Preheat broiler, with a rack 6 inches from heating element. Combine parsley and carrots in a bowl. Toss with cherry-pepper brine and oil; season with salt and pepper.

Step 2

Heat butter in a small saucepan with garlic, oregano, garlic powder, and 1/2 teaspoon salt until melted. Scoop out some of top of each roll to make room for filling. Brush split sides with garlic butter.

Step 3

Arrange mushrooms on a broiler pan; season with salt. Broil, flipping once, until tender and shriveled slightly, 10 to 12 minutes. Push to one side of pan and sprinkle with Parmigiano.

Step 4

Place rolls, split-sides up, on other side of pan. Broil 1 minute. Top mushrooms with provolone and broil until bread is golden brown and cheese is melted, 30 seconds to 1 minute more. Use a spatula to transfer half of mushroom mixture to bottom half of each roll. Top with cherry peppers and parsley salad, then other halves of rolls; serve immediately.