Preheat oven to 400 degrees. Score the skin side of the duck breasts on the diagonal in both directions. Season with salt and pepper to taste. Using a pastry brush, brush the breasts with honey. Transfer to a hot saute pan with 2 tablespoons butter and 1 tablespoon olive oil. Pan sear the duck breasts skin-side down until golden. Place the duck, skin-side-up in the pan in the oven and cook until rare, about 7 minutes. Slice the duck and fan around the bottom of the warm lentils and frisee.
In a medium stockpot, combine lentils, stock, salt and pepper to taste, thyme, and bay leaf. Cook until the lentils are just tender. Cool the lentils in the stock to room temperature. In a large saute pan over medium heat with butter and olive oil, saute bacon until just brown. Add onion, shallot, carrot, and celery. Saute until the vegetables are just tender, about 2 to 3 minutes. In a small saucepan over medium heat, warm the champagne vinegar and mustard. Season to taste with salt and pepper. Strain the lentils and add to the vegetables. Toss with the warm vinaigrette. Mix until just combined and warm. Place 3 slices of duck on top of a bed of frisee. Pile the lentils on top of the duck and fan duck slices around the bottom of the salad.