Using one of the most succulent and tastiest cuts of lamb, this marinated rack of lamb is paired with a creamy herbed parmesan polenta and a very tasty gravy.
Smear the marinade over the lamb and put into ziplock bags. Expel as much air as possible and seal.
Massage the marinade into the lamb.
Marinate the lamb in the refrigerator overnight.
Cook the rack of lamb
Preheat the oven to 200 degC fan on, or 220 degC with no fan.
Remove the marinating lamb from the refrigerator and remove the lamb rack from the marinade. Retain 4 Tbsp of marinade for the gravy.
Wipe the marinade off the lamb, and allow it to come to room temperature, around 30 minutes.
Cut the large onion into 1cm thick slices.
Grease the bottom of a roasting pan with some vegetable oil.
In a hot skillet, sear the lamb on the top and bottom.
Sit the lamb racks on top of the onion in the roasting pan. Lean them up against each other.
Roast the lamb for 15 minutes, turning the pan half way through.
Use a meat thermometer to ensure the internal temperature of the meat is around 55 degC for medium rare, or 60 degC for medium. If not there yet, pop back in the oven for another 5 minutes.
When the desired temperature has been reached, remove from the oven.
Transfer the lamb racks to a plate and cover with foil. Let rest for 15 minutes.
Retain the onion and juices in the roasting pan for the gravy.
Herbed Parmesan Polenta
Combine the water and polenta in a large bowl and allow to soak overnight.
Transfer the polenta and water to a saucepan and bring to a boil, stirring frequently.
Reduce to a medium-low heat and continue cooking for 30 minutes. Stir frequently. Use a spatula to scrap the sides and bottom of the saucepan.
Remove from the heat and whisk in the salt, olive oil, butter, and parmesan.
De-stem and coarsely chop the herbs.
When the polenta is cool enough to touch, stir in the herbs.
Gravy
Finely chop the shiitake mushrooms.
In a small saucepan, sauté the mushrooms in the butter for 5 minutes.
Add the chicken stock and water to the saucepan. Bring to the boil then reduce to a simmer.
When the lamb has been removed from the roasting pan, sprinkle the flour over the onions. The onions will be charred by this point, and there will be some meat juices from the lamb.
Put the pan over a medium low heat and stir the flour together with the meat juices and onion. When the paste formed by the flour and meat juices is bubbling, pour in the chicken stock.
Swirl around the pan, scrapping off any brown bits from the bottom.
Tip back into the saucepan and bring up to a high simmer.
Add the 4 Tbsp marinade and stir in. Simmer for 10 minutes. The gravy should thicken and darken.