Bring a pot of salted water to a boil. Add the pasta and cook as the label directs. Reserve 3/4 cup of the cooking water, then drain the pasta. Meanwhile, trim the thick stems off the cauliflower and coarsely grate the florets on the large holes of a box grater (it's fine if some small florets remain whole). Heat the olive oil in a large skillet over medium-high heat. Add the cauliflower, raisins, garlic, red pepper flakes and 1/4 teaspoon salt and cook, stirring occasionally, until the cauliflower is crisp-tender and slightly browned, about 4 minutes. Remove the skillet from the heat and stir in the pasta, parsley, dill, lemon juice, cheese and 1/2 cup of the reserved cooking water. Add more cooking water to loosen, if needed. Season with salt. Serve with more grated cheese.