Step 1

Mix 1 small red onion, thinly sliced, juice of 1 lime, and a big pinch of kosher salt in a small bowl. Let sit while you prepare remaining components for tortas, at least 15 minutes.

Step 2

Coarsely chop 2 chiles from one 7-oz. can of chiles in adobo. Mix chopped chiles, ½ cup mayonnaise, and 2 Tbsp. adobo sauce from can in another small bowl. Set chipotle mayo aside.

Step 3

Slice 1 medium globe eggplant (about 12 oz.) into ⅓"-thick rounds. Place ½ cup all-purpose flour in a shallow bowl. Lightly beat 2 large eggs in another shallow bowl to blend. Place 2 cups panko in a third shallow bowl; season each with salt. Working one at a time, dredge eggplant slices in flour, shaking off excess, then dip in egg, letting excess drip back into bowl. Dredge in seasoned panko, pressing to adhere. Transfer to a baking sheet.

Step 4

Pour vegetable oil into a large skillet to come ¼" up sides and heat over medium-high. Working in batches, cook eggplant until golden brown and crisp, about 2 minutes per side. Transfer to a wire rack and immediately season with salt.

Step 5

Spread reserved chipotle mayo over cut sides of 4 bolillo or ciabatta rolls, split. Build tortas with eggplant, 8 oz. quesillo (Oaxaca cheese) or fresh mozzarella, sliced, drained pickled red onion, 2 avocados, thinly sliced, ⅓ cup sliced pickled jalapeños, and ⅓ cup chopped cilantro.