Add the red peppers, kalamata and pimento-stuffed olives, garlic, red pepper flakes and some salt and pepper to the bowl of a food processor. Pulse a few times, adding enough olive oil to loosen the mixture to a loose paste. Taste and adjust the seasoning, adding more garlic or red pepper flakes if desired.
Spread the crostini with a bit of pesto and spoon on a big dollop of the tapenade. Garnish with fresh parsley and serve immediately.