In a high speed blender or food processor, add the sun dried tomatoes, pine nuts, garlic, and parmesan cheese. Blend until combined.
Slowly drizzle the olive oil in, blending regularly. Continue blending until thick and smooth.
Transfer the pesto into a bowl and let it sit for 30 minutes.
Notes
If your pesto is too thick, add more olive oil. TO STORE: Leftover pesto can be stored in the refrigerator, covered, for up to four weeks. TO FREEZE: Place the pesto in a sterilized jar and store it in the freezer for up to 6 months.