1. Sort beans for debris, then rinse. Bring beans and 2 quarts water to a boil over high heat in a 5- to 6-quart pan. Cover, boil for 2 minutes, and remove from heat. Beans are ready to cook after soaking for 2 hours, but are more digestible after 4 hours. Drain and rinse beans.
2. In a 6- to 8-quart pan, bring 2 quarts water, beans, 1 1/2 cups chopped onions, and garlic to a boil over high heat. Reduce heat and simmer, covered, for 40 minutes. Add 1 teaspoon salt and simmer until beans are just tender to bite, 30 to 40 minutes longer.
3. Drain beans and let cool in a bowl. Gently mix in remaining 1/2 cup chopped onion, parsley, oil, lemon juice, and pepper. Garnish with onion slices, and orange, lemon, and lime peels. Spoon over orange slices. Add salt to taste.