Bring a large pot of well-salted water to a boil.
Meanwhile, cook the pancetta in a 12-inch skillet over medium heat until golden, 4 to 6 minutes. Using a slotted spoon, transfer the pancetta to a small paper-towel-lined plate. Pour the pancetta fat into a small dish and measure 1 Tbs. of it back into the pan (if there's not enough, add olive or vegetable oil to make up the difference).
Return the skillet to medium heat. Add the onion to the pan, sprinkle with 1/4 tsp. each salt and pepper, and cook, stirring frequently, until the onion starts to soften and wilt, about 4 minutes. Add the zucchini, sprinkle with 1/4 tsp. salt and cook, stirring, until it starts to soften, about 3 minutes. Stir in the radicchio, broth, and mint and remove from the heat.
Meanwhile, cook the linguine in the boiling water according to package directions until it's barely tender. Reserve about 1/2 cup of the pasta water and then drain the pasta well. Return the pasta to its pot and add 1/2 cup of the parmigiano, the zucchini mixture, the balsamic vinegar, and 1/4 cup of the pasta water. Cook, stirring, over medium-high heat, until the pasta is tender and has picked up the flavors of the sauce, about 1 minute. Add more of the pasta water if the mixture becomes dry. Stir in the pancetta and season to taste with more vinegar, salt, and pepper. Serve sprinkled with the remaining 1/4 cup parmigiano.
nutrition information (per serving):
13, Fat Calories
120, Saturated Fat
24, Monounsaturated Fat
90, Polyunsaturated Fat
Photo: Scott Phillips