Place half the tortillas on a clean work surface and divide mozzarella evenly among them; top with remaining tortillas to form quesadillas.

Place quesadillas on a microwave-safe plate (we could fit three on one plate; it’s OK if they overlap a bit!). Microwave in batches until cheese melts, 1½-2 minutes.

Set aside to cool, flipping occasionally (this will help them cool evenly and hold together when you fry them in Step 4!).

Wash and dry produce.

Halve, peel, and thinly slice onion. Roughly chop cilantro. Quarter lime.

In a medium microwave-safe bowl, combine onion, vinegar, 1 tsp sugar, and 1 TBSP water (2 tsp sugar and 2 TBSP water for 4 servings). Season with salt.

Cover with plastic wrap and microwave until slightly softened, 1-2 minutes. Set aside to pickle, stirring occasionally.

Heat a large drizzle of oil in a large pan over medium heat. Working in batches, add quesadillas to pan in a single layer. Cook, turning once, until browned and crispy, about 1 minute per side. Repeat with remaining quesadillas, adding more oil between batches as needed.

Turn off heat; transfer quesadillas to a cutting board. (Reserve pan.)

Crack eggs* into pan used for quesadillas (add another drizzle of oil if needed) over medium-high heat and cover. (Depending on the size of your pan, you may need to cook eggs in batches.)

Fry eggs to preference. Season with salt and pepper.

Cut each quesadilla into six wedges (to resemble tortilla chips).

Divide quesadillas between plates; top with salsa, guacamole, and a drizzle of sour cream. Finish with eggs, cotija, pickled onion (draining first), and cilantro. Serve with lime wedges on the side.