Preparation steps:

Rinse rabbit and dry in a clean cloth. Season rabbit pieces with salt and pepper, and then dredge in flour. Melt 5 to 6 tablespoons of the butter in a wide frying pan over medium-high heat. Add rabbit, a few pieces at a time (do not crowd pan); cook, turning as needed, until browned on all sides.

Transfer rabbit to a shallow 4-quart baking pan. Move frying pan into an open area, away from exhaust fans and flammable items. Add brandy and ignite; shake or tilt pan until flame dies. Pour brandy mixture over rabbit in baking pan; set aside.
Melt remaining 2 to 3 tablespoons of butter in frying pan over medium heat. Add onions, minced parsley, minced tarragon and mushrooms; cook, stirring often, until onions are soft, about 5 minutes. Stir in mustard, cream, and lemon juice and bring to a boil. Pour sauce over rabbit. Cover and bake in a 375º F oven until rabbit is tender, about 45 to 55 minutes.
Drain cooking liquid into a wide frying pan and bring to a boil; boil for 4 minute. Beat some of the hot liquid into egg yolks, and then return yolk mixture to pan.
Cook, stirring constantly, until sauce is thickened, but do not boil. Season to taste with salt. Transfer rabbit to a serving dish. Pour sauce over rabbit and sprinkle with chopped parsley.