Bring 6 quarts water to a rolling boil and add 2 tablespoons of salt.
In a blender, place the mint, fennel fronds, basil, parsley, garlic, capers, tomatoes, black pepper, red pepper flakes, and half of the olive oil. Process in short bursts until roughly chopped. Turn blender on full speed and drizzle in the remaining oil. Process until almost smooth, about 1 minute. Remove the resulting pesto from the blender and place in a large bowl. Set aside for 1 hour.
Cook the pasta according to the package directions until just al dente. Drain well and place the cooked pasta in the bowl with the pesto, and toss like a salad to coat. Sprinkle the pasta with the grated locatelli pecorino and chili flakes.and serve.