Preheat the oven to 425 degrees F. Lightly grease a 9 by 9-inch baking dish.
In a large bowl, mix together the lamb, garlic, shallots, parsley and Parmesan. Season the meat with salt and pepper, to taste. Form meat into 1-ounce balls and arrange them in a baking dish. Bake them for 12 to 15 minutes. Remove them from the oven and keep warm.
In a large saute pan over medium-high heat, add the oil from the tomatoes. Add the garlic and red pepper flakes. Cook until the garlic begins to brown, about 1 to 2 minutes. Add the onions and cook until softened, about 2 to 3 minutes. Stir in the spinach and tomatoes and cook until warmed through and mixture has good color, about 4 to 5 minutes. Add the lemon juice and season the mixture with salt and pepper, to taste. Whisk in the mascarpone cheese and remove the pan from the heat. Put 3 to 4 meatballs on each roll and top with the sun-dried tomato and spinach salad.