Steam the glutinous rice and couscous with enough chicken stock to cover.
Slice the lamb loin into very thin pieces, season with salt, pepper and cumin. Then pan-sear the lamb until half-cooked. Blanch the spinach and then plunge into cold water. Dry them and lay them flat on a tray. Spoon some cooked couscous and glutinous rice onto each leaf, firmly pat it down, then add the pan-seared lamb slices. Top the lamb with chives and parsley, then sprinkle some Martell Cognac over, roll into a roulade, slice in two and serve.