Bone out the rabbit saddles. Use the bones to make stock for the sauce (or use chicken stock). Reduce the stock as necessary to concentrate it.
Heat the butter over low heat and add the shallots, carrots, zucchini, mushrooms, and garlic. Sweat until tender but not browned. Do not cover, so moisture can evaporate as it cooks out of the vegetables.
While the vegetables are cooking, purée the liver and force it through a sieve. Measure 1 tbsp (15 g) for each 4 portions (2 oz or 60 g for 16 portions).
Mix the basil, parsley, and puréed liver with the hot vegetables. The heat of the vegetables will cook the liver instantly.
Stir in the bread crumbs. Season to taste with salt and pepper. Cool completely.
Lay the saddles on the worktable, skin side down. Replace the tenderloins, placing the thick end of the tenderloin against the thin end of the loin, so that the meat is of more uniform thickness.
Spoon the vegetable mixture down the center of each saddle. Roll up the saddles into a sausage shape to enclose the stuffing. Tie securely. Refrigerate until ready to cook.
Cooking:
Brown the saddles well on all sides in oil. Transfer to an oven heated to 450°F. Roast for 15 minutes.
Remove the saddles from the pan and keep warm. Degrease the pan. Deglaze with vermouth and reduce by half.
Add the rabbit or chicken stock and the vegetable stock. Reduce by two-thirds. Finish the jus with butter. Season to taste.
Presentation:
Enrich the potatoes with extra butter. They should be quite soft.
For each portion, place a tbsp (15 g) of potatoes on each quadrant of the plate.
Cut each saddle into 4 slices. Place each slice on top of each dab of potatoes, with the most attractive side of the slice up. (If using larger saddles yielding 2 portions each, modify the presentation as necessary. For example, cut the saddle into 6 slices, 3 per portion. Six slices from larger saddles will be thinner but broader.)
Place a mound of chard (or spinach) in the center of each plate.
Place a few pieces of diced carrot and zucchini on the plate between the slices.
Spoon the jus onto the plate around the meat.