What's not to love about delicious and delightful things pressed between two slices of bread? If you want a yummy, rich, spicy, cheesy, toasted sandwich, this is one I highly recommend.
Swap option: If you want a spicier version, add more chipotle peppers to the mayo or don't seed the jalapeño for the pesto. Less spicy, less chipotle, and less jalapeño. If you have any leftover pesto, use it to top grilled chicken.
For the Southwestern pesto:
Pulse the cilantro, garlic, jalapeño, lime juice, and salt in a food processor, fitted with the metal blade, 12-15 times or until finely chopped. With the machine running, slowly add the oil through the feed tube and process until a paste forms. Scrape the pesto into a small bowl. Set aside.
For the chipotle mayo:
Mince the chipotle peppers and add a bit of the adobo sauce, as needed, to measure 2 tablespoons. Stir together the mayonnaise, chipotles, and sugar in a small bowl.
For the panini:
Spread the butter on 1 side of each bread slice. Turn the slices over, buttered sides down. Spread 4 bread slices with the chipotle mayonnaise and the other 4 bread slices with the cilantro pesto. Top 4 of the slices with the cheese and chicken, and top with the remaining bread slices, buttered sides up.
Cook the sandwiches in a large nonstick skillet (or griddle or panini press) over medium 2-3 minutes on each side or until golden brown and the cheese is melted.