Soften the butter. Grate the lemon zest. Mix with 2 tsp of lemon juice and the honey. Combine 1 tsp with the soft butter, season with salt. Set aside the remainder for the meat marinade.
Spread half of the butter (approx. 1.5 cm thick) onto a sheet of foil. Mix the rest of the butter with the balsamic, season and spread over the top.
Roll up the butter and chill for approx. 2 hrs.
Finely chop the thyme, add to the reserved lemon & honey mixture. Crush in the garlic. Add the oil and pepper, mix well. Coat the lamb racks with the mixture, cover and marinate at room temperature for approx. 1 hr.
Pat off some of the marinade, salt the meat. Heat the clarified butter in a frying pan, reduce the heat. Over a low heat, brown the meat all over for approx. 15 mins., only turning when a crust has formed.
Turn off the hob, cover the lamb racks and leave to infuse for approx. 15 mins. on the hot hob (the core temperature should be approx. 55°C).
Peel the bottom third of the asparagus. Slice the asparagus diagonally into quarters.
Heat the oil in a frying pan. Sauté the asparagus, season with salt. Add the water, lemon juice and sugar, simmer the asparagus for approx. 20 mins. until almost soft.
Slice the balsamic lemon butter. Carve the lamb racks, serve with the asparagus and balsamic lemon butter.