Step 1

Whisk oil, lemon juice, pomegranate molasses, Aleppo-style pepper, sumac, and garlic in a medium bowl; season with salt and pepper. Let sit 5 minutes, then fish out and discard garlic. Stir in onion; let sit until ready to use.

Step 2

Heat 2 Tbsp. oil in a large nonstick skillet over medium-high. Season fish with salt and lightly coat flesh side with dressing. Cook fish, skin side down, until skin is browned and crisp, about 3 minutes. Turn over; cook until flesh side is browned and fish is just cooked through, about 2 minutes. Transfer to a plate.

Step 3

Drizzle cut sides of rolls with oil. Divide fish among bottom halves and top with tomato; season with salt. Add arugula, carrot, and mint to dressing and toss to coat. Mound on top of tomato; close up sandwiches.