Prepare a grill for high heat. Halve the Cubanelle peppers lengthwise, trim the tops and remove the seeds. Drizzle the peppers, tomatoes and onion rounds with oil, and sprinkle with 1/2 teaspoon salt. Place the vegetables on the hot grill, cut-side down, and cook 6 to 7 minutes, flipping halfway through, to get some charred areas and dark grill marks. Set aside the grilled pepper halves.
Put the grilled tomatoes and onion, garlic, chipotles, cilantro, juice of 1 lime and 1 1/2 teaspoons salt in a food processor, and pulse about 20 times for a chunky salsa.
Cut the avocados in half, remove the pits and scoop out the flesh with a spoon into a medium bowl. Add the remaining lime juice and 1/2 teaspoon salt. Mash the avocado lightly with a fork so that some large pieces remain.
Stuff about 2 tablespoons of the Monterey Jack into each pepper half. Place a piece of aluminum foil, large enough to hold all the peppers, on the grill. Arrange the stuffed pepper halves on the foil. Cover the grill to melt the cheese, about 4 minutes.
Heat the tortillas on the grill for about 30 seconds to 1 minute per side for light grill marks. Wrap the tortillas in aluminum foil to keep them warm and soft.
To assemble a taco, spread some of the avocado on a tortilla. Top with a stuffed pepper half, followed by a spoonful of salsa, a dollop of the sour cream and some torn cilantro leaves.
Copyright 2014 Cooking Channel, LLC. All rights reserved.