Make sauce --
In medium bowl, whisk together crème frîache, honey, cumin, coriander, salt, and pepper. Sauce can be made up to four hours in advance, covered, and refrigerated until ready to use. --
Braise lamb ribs --
Preheat oven to 300°F.
Pat ribs dry and sprinkle with salt and pepper. In heavy large sauté pan over moderately high heat, heat olive oil until hot but not smoking. Working in batches, sear ribs until golden brown, 4 1/2 to 5 minutes per side. Transfer ribs as done to platter; do not wash pan.
In same pan, combine onions, carrots, celery, garlic, and rosemary. Sauté, stirring often, until soft, about 15 minutes. Add red wine and bring to boil. Lower heat to moderate and continue simmering until reduced by about 10 percent, about 3 minutes. Add stock and bring to simmer. Return ribs to pan, cover, and braise in oven until desired doneness (125°F for medium-rare, about 1 hour). Transfer ribs to cutting board and let stand 15 minutes. Lower oven to 125°F --
While ribs are braising, make salad --
Have ready large bowl ice water. In medium saucepan over high heat, bring salted water to boil. Add peas and boil, uncovered, until tender, 2 to 3 minutes. Drain in colander, then immediately plunge colander into ice water to stop cooking. Drain again. Coarsely chop, transfer to medium bowl, add onion, and toss to combine.
In small bowl, whisk together olive oil, lemon juice, salt, and pepper. Drizzle over pea-onion mixture and toss to combine. --
Finish ribs and serve --
In heavy large sauté pan, heat vegetable oil until hot but not smoking. Cut racks into individual ribs.
In medium bowl, whisk together flour, semolina, and Parmigiano-Reggiano.
Working in batches of 6, dredge ribs in flour mixture and fry until golden and crisp, 2 to 2 1/2 minutes per side. Transfer as done to paper towel-lined plate. Keep warm in oven while frying remaining batches.
Ladle sauce into middle of large platter. Pile ribs on top, then top with salad. Sprinkle with cumin, coriander, and salt and serve immediately.
