Add all ingredients, except for the water, to a food processor with a standard blade attachment. A high powered blender can also be used. Process until mostly broken down. Stop and add 1 tablespoon water to thin, scraping down food processor sides as needed.
Process until smoothly pureed. Taste for salt and pepper. Serve topped with fresh chopped rosemary and a drizzle of olive oil. Enjoy warm or cold.
Cannelini or other white beans can be used in place of great northern beans.
Crock-pot option: Add prepared white bean dip to a 1 and ½ quart slowcooker. Heat on low for 3-4 hours, until warmed through. Keep warm in slow-cooker if serving as an appetizer.