Preheat oven to 400° F.
Mix lemon zest, lemon juice, garlic and chipotle pepper. Divide equally into 2 bowls.
Rub a small amount of olive oil on fish. Top fish with half of chipotle mix. Sprinkle with salt and pepper.
Bake 8 minutes or until done.
Assemble sandwiches on rolls with fish, chipotle mayonnaise, onion and lettuce.
Chipotle Mayonnaise: In a medium bowl, mix all ingredients until well blended.
Serves 4