Heat the oil in a skillet. Add the onion and sauté over moderate heat until translucent. Add the garlic and continue to sauté until the onion is just beginning to brown.
Combine the onion mixture with all the remaining ingredients except the salt and pepper in the container of a food processor and process until completely smooth. Drizzle in 2 tablespoons of water or so, to loosen the consistency. Stop and scrape down the sides as needed.
Season with salt and pepper. Pat into an attractive shallow crock to serve. Place on a large platter and surround with whole-grain crackers and crispbreads.