Stir together mayonnaise and chipotles and set aside.
Preheat a panini press* to 350° (medium heat). Brush the outsides of rolls with oil. Split rolls. Spread bottom halves with 1 1/2 tsp. chipotle mayo each, then top each with 2 slices cheese; 2 or 3 slices roast beef; 1 chile, opened up flat; and 2 more slices cheese.
Spread top halves of rolls with 1 1/2 tsp. chipotle mayo each and place on tops of sandwiches. Grill sandwiches 2 at a time until crisp and bubbling, 3 to 4 minutes. Repeat with remaining 2 sandwiches. Let sandwiches cool slightly, then slice with a serrated knife and serve.
*If you don't have a panini press, use two pans to achieve the same effect: Cook your sandwiches in a frying pan or cast iron skillet and weight them with a heated cast iron skillet.
Note: Nutritional analysis is per sandwich.