Roasted Lamb with Grain Mustard and Soy Sauce

Lisl first made this lamb roast not long after we met. If I went for sensational titles I’d call this the “how to impress your new boyfriend without slaving in the kitchen, but make him think you did” lamb roast.  It actually remains my favorite way to cook lamb by a long shot, and it is so easy to do that it isn’t really a recipe but a simple process (which is one reason why I have time to blog it at the moment).

Lisl prefers to do this roast with a leg of lamb, but we used a boneless lamb sirloin roast and while it fell apart a bit when slicing, I found this cut to be incredibly good.  I also loved the gratin we served with it, which I’ll describe at the bottom of the post.

30 minutes before starting the roast, place the lamb in a baking dish and slather grain mustard all over the meat (for this 3lb roast, I think Lisl used about 4 tbsp), and then generously drizzle soy sauce all over.  Pre-heat the oven to 425F.

Roast the lamb for 10 minutes, and then lower the heat to 325F.  Turn the lamb over every 20 minutes or so, and cook until the internal temperature reaches 130F (an instant read thermometer is really handy here). Remove the lamb to a cutting board and loosely cover with aluminum foil until you are ready to slice and serve.

Place the baking dish on the stovetop — we use our pyrex right on the flame, but if you are working with porcelain, use a heat diffuser.  Deglaze the baking dish with water and a tablespoon or two of flour to make the gravy.  It will be very salty, but a little drizzle over the lamb and you’ll be in heaven.

We served this with two sides: a potato, fennel and chard-stem gratin, and the chard greens sauted with shallots and a touch of lemon juice.

I loved this gratin.  It was the same process and basic ingredients as my adaptation of Ina Garten’s potato and fennel gratin (click link for recipe), but this time I added chard stems to the fennel and onion (which is sauted before putting the gratin together).  I also used a mix of gruyere cheese and parmesan cheese.  So good. It is a dish well suited for cooler weather (and we’ve been having very cool, wet weather).