Definitions:

Langostino is a Spanish word with different meanings in different areas. In America, it is commonly used in the restaurant trade to refer to the meat of the squat lobster, which is neither a true lobster nor a prawn. It is more closely related to porcelain crabs and hermit crabs. You may use prawns if you cannot find the specific.

Aji Mirasol is a Peruvian red pepper. You may use regular ground red (cayenne) pepper in a pinch with some flavor loss, but you're really better off if you can find ground New Mexico chili powder.

Aji Panca is another Peruvian pepper. It has medium thick flesh and a smoky berry flavor. This one's really tough to substitute. Try Poblano or any other mild but flavorful ground chile.