Place the pine nuts and fennel seeds in a dry skillet over medium heat. Stir and flip the nuts frequently for 3-4 minutes until the pine nuts are lightly browned and the fennel seeds are fragrant. Transfer to a plate and let cool fully.

Add the cooled pine nuts and fennel seeds to a food processor. Add the drained sun-dried tomatoes, basil, garlic, red wine vinegar, crushed red pepper flakes, and salt. Process for about 60 seconds until the mixture is finely chopped and forms a thick paste. Scrape down the sides of the bowl as needed so the mixture processes evenly.

With the machine running, slowly pour in the olive oil in a steady stream so the mixture emulsifies and becomes smoother.