Thinly slice the fennel stalks. Finely chop enough of the fronds to make 3 tablespoons. In a shallow dish, combine the stalks, wine, garlic, lemon zest, and red pepper. Add the lamb chops and turn to coat. Let stand at room temperature for 1 hour, turning the chops once halfway through.

Pat the lamb chops dry. Strain 1/2 cup of the marinade and reserve. In a very large skillet, heat 2 tablespoons of oil. Season the chops with salt and pepper, add them to the skillet and cook over moderately high heat until browned, 4 minutes. Turn the chops, reduce the heat to moderate and cook until medium-rare, 4 minutes; transfer to a plate and let rest.

Pour off the fat in the skillet. Add the reserved 1/2 cup of marinade and boil over high heat, scraping up the browned bits from the bottom of the skillet, until reduced by half, about 2 minutes. Add the chicken stock and boil until reduced to 1/4 cup, about 4 minutes. Reduce the heat to low and stir in the creme fraiche. Remove the skillet from the heat. Add 1 tablespoon of the chopped fennel fronds and season with salt.

In a bowl, toss the sliced fennel bulb with the lemon juice, and the remaining 2 tablespoons each of the oil, and fronds. Season with salt and pepper. Transfer the salad to plates and top with the chops. Spoon the sauce over the chops and serve.