This one-pot pasta dish lets pantry ingredients do the heavy lifting. Fennel seeds, red pepper flakes and rosemary are bloomed in olive oil to release their essential oils before a full can of tomato paste, which provides a bulk of the flavor backbone, goes into the mix. Cooking the paste until browned develops flavor compounds that make this vegetarian dish rich and savory. Of course, the cheese helps, too. Diced fontina melts into the pasta, creating a creamy, unctuous texture; Taleggio also is a delicious option. We prefer lacinato kale, which sometimes is sold as Tuscan or dinosaur kale. Bunches vary in size; you’ll need about 1 pound—one large bunch or two small ones—so if in doubt, toss the kale onto the produce scale at the supermarket.