Making the” salsa. Scoop the tomatoes, chiles, cilantro, garlic and white onion into a bowl and mix well. Stir in the hot sauce, ketchup and optional lime juice. Taste and season with salt, usually about a scant teaspoon.
Making the shrimp filling. Heat a very large (12-inch), heavy skillet—nonstick works really well—over medium-high. Pour in 2 tablespoons of the oil and when it is hot, add the “salsa” vegetables. Cook, stirring regularly, until everything softens together, about 5 minutes. Scoop in the shrimp and stir until they are barely cooked through (they can still be slightly translucent at the center)—about 3 minutes. Scoop the shrimp mixture into a bowl, wash and dry the skillet, and return it to medium heat.
Assembling the encamaronadas. Heavily film the bottom of the skillet with oil. When hot, lay in a tortilla. After a few seconds, flip it, then scatter a couple of tablespoons of shredded cheese over one side, top with a generous tablespoon of the filling. Use tongs to fold the uncovered part of the tortilla over the filling, forming a turnover. Gently press flat. Continue to make encamaronadas in the same fashion until the skillet is full, frying them until crisp—2 to 3 minutes per side. As they become crisp, remove them to a plate lined with paper towels. Serve right away with more Mexican hot sauce.