Tex Mex Ultimate Carnitas Grilled Cheese

Name: Tex Mex Ultimate Carnitas Grilled Cheese
Ingredients: 1/3 cup sour cream; 1/4 cup minced pickled jalapeno peppers; 6 tablespoons mayonnaise, divided; 1 tablespoon pickled jalapeno pepper juice; 1 small garlic clove, minced; 1/4 teaspoon sea salt; 2 tablespoons vegetable oil; 2 cups carnitas (cooked pulled pork); 1 1/2 cups shredded pepperjack cheese; 1 1/2 cups shredded sharp Cheddar cheese, divided; 8 thick slices bread (such as Texas toast); 1 large avocado - halved, pitted, and thinly sliced; 1 cup cilantro leaves