How to Make It
In a small bowl, combine the onion with the lime zest, lime juice and a small pinch of salt; let stand for 15 minutes. Drain the onion; reserve the onion and lime juice separately.
Meanwhile, sprinkle the chicken with 1/2 tablespoon of the adobo seasoning and arrange in a single layer on a microwave-safe plate. Microwave the chicken on high power in 2-minute intervals, turning once, until just cooked through, about 7 minutes. Let cool slightly.
In a wide, shallow bowl, whisk the flour with the cornmeal, paprika and the remaining 2 1/2 tablespoons of adobo seasoning. In a medium bowl, whisk the egg whites until foamy, about 1 minute. Dip the chicken pieces in the egg whites, letting the excess drip back into the bowl, then dredge them in the flour mixture; tap off any excess.
In a large saucepan, heat 6 cups of the oil to 400°. Fry the coated chicken pieces in 2 batches until golden brown, about 12 seconds per batch. Transfer the fried chicken to a paper towel–lined plate and season with salt and pepper.
In a large bowl, toss the lettuce with the cilantro, tomatoes, jalapeño, the reserved onion, 3 tablespoons of the reserved lime juice and the remaining 2 tablespoons of oil; season with salt and pepper. Serve the fried chicken with the salad, avocado and lime wedges.
The Latin spice blend adobo, with garlic, oregano, pepper and turmeric, is available at many supermarkets.