01 - Combine softened butter, adobo sauce, chopped chipotle pepper, and minced garlic in a mixing bowl until uniform.
02 - Evenly coat one side of each bread slice with chipotle butter mixture using a butter knife or spatula.
03 - Place two bread slices, buttered side down, on a work surface. Distribute cheddar and Monterey Jack cheese evenly over the bread. Add optional jalapeño slices and cilantro.
04 - Top each with remaining bread slices, buttered side up, completing the sandwiches.
05 - Preheat a nonstick skillet or griddle over medium-low heat. Arrange sandwiches in the pan and cook for 3 to 4 minutes per side, pressing gently with a spatula until bread is golden and cheese melts.
06 - Remove sandwiches from heat, let rest for 1 minute, then slice with a chef’s knife and serve hot.