Season the lamb well with salt and pepper, rubbing the seasonings into the meat. Heat a large cast iron skillet over medium-high heat and lay the seasoned rack, fat side down, into the pan. Sear the lamb until the fat is golden brown or until the fat has rendered, about 3 minutes or so. Flip and brown the meaty side and ends of the rack. The browning should take about 10 minutes. Adjust the heat as necessary so the fat is sizzling, not sputtering. Transfer the rack of lamb to a plate to cool and set the skillet aside, but don't wash it.
Heat the oil in a medium skillet over medium heat. Add the minced onion and garlic and cook until softened and fragrant about 3 minutes. Stir the bread crumbs into the skillet until coated with the onion mixture. Lower the heat and add the cumin, oregano, chili powder, and salt and pepper, to taste. Stir constantly to prevent scorching until the bread crumbs are toasted and golden, about 4 minutes. Remove from the heat and stir in the lime zest.
Preheat the oven to 425 degrees F.
Put the roasted pepper, chipotles and adobo sauce in the work bowl of a food processor. (If you have a mini-processor, use it here.) Process until smooth, stopping to scrape down the sides of the work bowl once or twice.
Using a small spoon, paint the flat/bone side (not the rounded, meaty part) of the rack with enough of the pepper paste to coat it generously. Sprinkle the toasted bread crumb mixture over the painted lamb and press lightly to make sure the crumbs adhere to the lamb. Stand the rack, bone side up in the skillet used to sear the lamb, and place in the preheated oven. Roast for 20 minutes for medium rare. (An instant-read thermometer inserted into the thickest part of the rack should register 125 to 130 F degrees F.) Remove to a cutting board and let rest for 10 minutes.
Carve the rack between the bones into double chops and serve immediately.
Note: "Frenched" racks of lamb have had the meat and fat trimmed from both sides of the last inch or so bone as well as all the fat and meat removed from between the bone tips. Frenching gives lamb racks a finished, elegant look. Many supermarkets and big box stores sell fresh or frozen vacuum-sealed Frenched racks of lamb imported from New Zealand.
Note: There will be more of the "dos chile" paste and the toasted bread crumbs than needed to coat the rack. The chile paste is delicious in soups, stews, beans and many other uses.