Add the cayenne pepper, salt, fennel seeds, and ground pepper to a spice grinder (or mortar) and grind fine.
Drain the sundried tomatoes and keep the oil to the side.
Add the tomatoes and the spices to a small food processor. Add 1 or 2 tablespoons of the retained oil. Blend until smooth. Stir in more oil to reach your desired consistancy.
Use immediately, or for best flavor, allow the paste to settle (covered, in the refrigerator) overnight to allow the flavors to meld.