Preheat the oven to 375 degrees . Season the lamb with salt and pepper. Heat a large nonstick skillet over high heat. Add 1 rack of lamb, fat side down, and cook until golden brown, about 3 minutes; move to the side of the pan. Repeat with the second rack. Lean the racks against each other so they stand upright and cook for 2 more minutes.
In a medium nonstick skillet, heat the olive oil over medium heat. Add the onion and garlic and cook until soft, 2 to 3 minutes. Stir in the bread crumbs, lower the heat and add the oregano, chili powder and cumin. Season with salt and pepper. Cook, stirring constantly, until toasted, about 2 minutes. Remove from the heat and stir in the lime peel.
Using a food processor, puree the chipotles and adobo sauce and the roasted red pepper. Brush the meaty side of the racks of lamb with the puree. Sprinkle with the toasted bread crumb mixture, pressing to coat. On a baking sheet, lean the racks against each other. Roast for 25 minutes for medium-rare.