Governor's Tacos - Rick Bayless

Ingredients

• 2 tbsp butter
• 1 medium fresh poblano chile quartered lengthwise, seeds and stem removed, thinly sliced crosswise
• 1 small onion, chopped into 1/4-in. pieces
• 3 garlic cloves, finely chopped
• 1 medium (6 oz.) tomato, cored and chopped into 1/4 in. pieces
• 1 or 2 fresh hot green chile (such as serrano or jalapeño), finely chopped (optional)
• 1 pound smallish shrimp (51-60 per pound), peeled, deveined if you wish, chopped into 1/2 in. pieces
• 2 tsps Worcestershire
• 1 generous tbsp tomato paste
• kosher salt
• 4 cups mexican melting cheese (such as Chihuahua, quesadilla or asadero) or Monterey Jack, brick or mild cheddar
• 12 corn tortillas or 8 (8-in.) flour tortillas
• 2 tbsp vegetable oil (to brush or spray on corn tortillas only)