While bringing a large pot of salted water to a boil, mince the garlic cloves, halve the cherry tomatoes, chop the fresh basil and parsley leaves, slice the scallions, and cut the avocado in half lengthwise, remove the pit, and scoop the flesh into a bowl. Once the water is boiling, add the pasta and cook according to package directions until al dente (usually 9-11 minutes for linguine). Reserve 1 1/4 cups of pasta water before draining, then set the cooked pasta aside.
Add the prepared avocado, basil, parsley, scallions, minced garlic, lemon juice, grated parmesan cheese, extra virgin olive oil, sea salt, and black pepper to a food processor. Blend until completely smooth and creamy, about 1-2 minutes. I like to pulse it a few times before fully blending to ensure there are no chunks of avocado—this gives you the silkiest sauce possible. If the mixture seems too thick, add a splash of the reserved pasta water to loosen it slightly.
Return the cooked pasta to the pot or a large bowl. Pour the avocado cream sauce from Step 2 over the pasta, then add the diced cooked chicken breast and red pepper flakes. Toss everything together gently but thoroughly, adding the reserved pasta water gradually—a little at a time—until you reach your desired consistency. The sauce should coat each strand of pasta silkily without being too thick or too thin. I find that starting with about 3/4 cup of the pasta water and adjusting from there works best, as you want the sauce to cling to the pasta rather than pool at the bottom.
Divide the creamy avocado pasta among serving bowls or plates. Top each portion with a light sprinkle of additional parmesan cheese and a pinch of smoked paprika for color and depth. Arrange fresh rocket leaves and the halved cherry tomatoes (from Step 1) on the side or on top of the pasta for freshness and a pop of acidity that balances the richness of the avocado sauce.
Serve the plated pasta immediately while it's warm, with warm slices of sourdough bread on the side for soaking up any extra sauce and enjoying with the meal.