Cheesy Shrimp Tacos - Rick Bayless

Ingredients

• 12 ounces (2 medium-small round or 4 or 5 plum) ripe tomatoes, cut into ¼-inch pieces
• Fresh serrano chiles to taste, (roughly 3 to 5), or even more if you like it really picante), stemmed, seeded if you wish, and finely chopped
• 1/4 cup chopped cilantro, thick bottom stems removed
• 1 large garlic clove, peeled and very finely chopped
• 1 small white onion, finely chopped
• 1 tablespoon Mexican hot sauce (such as Valentina or Tamazula), plus extra for serving
• 1 tablespoon ketchup
• 2 teaspoons fresh lime juice (optional, but you might like the zing it adds)
• Salt
• About 1/3 cup vegetable oil, divided use
• 1 pound small shrimp, peeled, deveined if you wish, and chopped into pieces a little smaller than ½ inch
• 15 corn tortillas
• 8 ounces shredded Mexican melting cheese (full-flavored Chihuahua or Jack cheese work best)