Step 1

To make the salsa, in a food processor, combine the tomatoes, onion, garlic, oregano and 1 teaspoon salt. Process until smooth, 1 to 2 minutes. Transfer to a medium bowl; reserve the food processor bowl and blade. Stir the cabbage and cilantro into the puree, then taste and season with salt and pepper. Cover and set aside until ready to serve.

Step 2

To make the tacos, in the food processor, combine the tomatoes, onion, garlic, oregano, 1 teaspoon salt and ¼ teaspoon pepper. Pulse to a coarse puree, about 10 pulses. Transfer to a small bowl. To the food processor, add the shrimp and pulse until finely chopped, about 4 pulses.

Step 3

In a 10-inch skillet over medium, heat the 3 tablespoons oil until shimmering. Add the tomato-onion puree and cook, stirring occasionally, until most of the moisture has evaporated, 7 to 9 minutes. Add the flour and cook, stirring, until well incorporated, about 1 minute. Add the shrimp and cook, stirring constantly, until the shrimp turn pink and the mixture has thickened, about 1 minute. Set aside off heat.

Step 4

Heat a 12-inch skillet over medium until water flicked onto the surface immediately sizzles and evaporates. Add 2 tortillas in a single layer (it’s fine if they overlap slightly) and heat, flipping them once, until warm, about 30 seconds per side. Transfer to a kitchen towel and wrap loosely to keep warm and pliable. Repeat with the remaining tortillas, stacking and wrapping them in the towel. Add the remaining 1 cup oil to the skillet; keep warm over low while you fill the tortillas.

Step 5

Lay 4 of the tortillas on a work surface and divide half of the shrimp mixture evenly among them, placing the filling on one side of the tortilla. Fold the unfilled sides over and press lightly; leave the edges open (do not seal them). Fill the remaining tortillas with the remaining shrimp mixture in the same way.

Step 6

Return the oil to medium and heat until shimmering (about 350°F). Carefully add 4 of the tacos and cook until golden brown and crisp on the bottoms, about 3 minutes. Using a thin metal spatula, flip each taco and cook until golden brown on the second sides, about 3 minutes, then transfer to a paper towel-lined plate. Fry the remaining tacos in the same way, adjusting the heat as needed.

Step 7

Transfer the tacos to a serving platter and spoon on some of the salsa. Top with the avocado slices and serve with the remaining salsa and lime wedges on the side.