Preheat oven to 350F. Heat fat in a large skillet and saute carrots, celery, onion, and garlic over medium-high heat for about 8 minutes until soft.

Grind chickpeas and scallions using the steel blade of a food processor or a food mill. Combine all ingredients in a large bowl and mix well. Transfer to a well-oiled 9 1/2 x 51/2-inch loaf pan. Tap on the counter to remove any air bubbles. Cover with foil and bake for 1 hour.

Cool in the pan before removing. Serve warm or chilled in individual slices on a bed of greens. Decorate with strips of sweet pepper or other garnish.