Preheat the oven to 400 degrees . In a medium saucepan, warm the chicken broth over low heat. In another medium saucepan, heat 2 tablespoons EVOO, 2 turns of the pan, over medium heat. Add the onion and garlic and cook for 2 minutes. Add the rice and cook, stirring, for 1 minute. Stir in the wine and cook for 1 minute. Stir in the warm broth one ladleful at a time, allowing the liquid to evaporate before adding more. Cook for 13 minutes more.
On a baking sheet, toss the green beans, tomatoes and scallions with the balsamic vinegar and 2 tablespoons EVOO; season with salt and pepper. Roast for 15 minutes.
In a large skillet, heat the remaining 1 tablespoon EVOO, 1 turn of the pan, over medium heat. Season the lamb chops with salt and pepper, add to the skillet and cook for 3 minutes on each side for rare.
Using a food processor, puree half of the peas with the mint and parsley; season with salt and pepper. Stir the mixture into the risotto, then stir in the remaining whole peas, the parmigiano and butter.
Serve the lamb chops with the risotto and roasted vegetables.