For me, small carrots and parsnips symbolize the beginning of the spring season. This stew recipe celebrates that for me.
Preheat the oven to 325 degrees F.
Heat a Dutch oven over high heat and add the oil. Season the pieces of lamb on all sides with salt and pepper, to taste. When the oil begins to smoke lightly, use a pair of metal tongs to arrange the lamb, in a single layer, in the hot oil. Brown the meat on all sides. Remove the meat to a medium bowl. Stir in the onions and season them lightly with salt. Cook until tender, 2 to 3 minutes. Stir in the garlic, parsnips and carrots. Season with salt, to taste, and add the brown sugar. Cook until the vegetables become slightly tender, 8 to 10 minutes.
Add the vermouth and cook until all of the liquid cooks out, an additional 5 to 8 minutes. Stir in the mustard, beef stock and add the bay leaves. Add the lamb back into the pot, then cover and put it in the center of the oven. Cook until the meat is tender when pierced with the tip of a knife, 1 to 1 1/2 hours. Remove the stew from the oven and use a large spoon to skim any excess fat or impurities form the surface of the sauce. Taste for seasoning and remove the bay leaves. Stir in the peas. Allow it to "rest" for 15 minutes before serving. Stir in the mustard greens and transfer to a serving bowl. Serve immediately.