In a large pan of salted water, bring the spaghetti to a boil. Cook according to package directions until there are four minutes left of cooking time.
When there are four minutes left of cooking time, remove and reserve 1/4 cup of the salted cooking water. Add in the Happy Fish and continue to cook for the remaining four minutes.
Drain the water from the pasta and Happy Fish. Carefully stir in the sun-dried tomato pesto. If the pasta is too dry, add a touch of the reserved pasta water.