A briny topping makes these hors d'oeuvres perfect for cocktail hour.
Process garlic in the bowl of a food processor until finely chopped. Add chickpeas; pulse until crushed but not pureed, 7 to 8 pulses. Transfer to a small bowl. Add pimientos, olive oil, cumin, and parsley; stir to combine. Season with salt and pepper.
Place about 1 tablespoon mixture on top of each crostini. Garnish with a parsley leaf and a slice of pimiento, and serve.