01 -
Mix together the mustard, soy sauce, garlic, all dried herbs, and ginger in a bowl. Slowly blend in the olive oil until it looks like mayonnaise. Cover the lamb all over with this paste. Place it on a rack in a roasting pan, keeping the fatty side on top. Set aside for 2 hours at room temp.
02 -
Bring your oven up to 425°F. Inside the roasting pan, scatter the chopped onion, lemon rounds, and those fresh herb sprigs below the rack.
03 -
Pop into the oven and roast the lamb for half an hour at 425°F.
04 -
Turn the temperature down to 350°F. Keep cooking until the meat hits the doneness you like: roughly 135°F for a nice medium-rare, or closer to 145°F for medium. This could take another 1.5 hours or so. Around the 1-hour mark, pour in 2 cups of broth, then add more (as needed) after 30 minutes.
05 -
Take the lamb out when it’s 5 degrees cooler than your goal. Put it on a cutting board, cover it loosely with foil, and let it relax for 20 to 30 minutes.
06 -
Pour the pan drippings into a cup, skimming off any fat. If it’s not 2 cups, add enough stock to fill it. Stir the flour and water to form a paste. Heat the pan on high, splash in the wine, and let it reduce until it’s half gone. Stir in the reserved juices. With steady whisking, add the flour mix a little at a time, and let the sauce bubble gently till thickened (5-10 minutes). Finish by seasoning with salt or pepper.
07 -
Snip off the string or netting around the roast, then carve into slices and serve with the gravy.