Liberian Black Eyed Pea Soup

Name: Liberian Black-Eyed Pea Soup
Ingredients: 1 cup dried black-eyed peas; 2 garlic cloves (peeled ); 6 cups water, divided; 2 cups chopped onions; 1 cup diced celery; 2 tablespoons water; 1 pinch cayenne (more to taste ); 2 teaspoons ground allspice; 1 pinch dried thyme; 1 green bell pepper (or red, seeded and chopped ); 1 cup fresh corn kernels (or frozen) (optional); 1 cup sliced okra (fresh or frozen ); 2 cups chopped fresh collard greens (or kale or chard or spinach) (optional); 3 cups diced tomatoes with juice (28-ounce can); 1 tablespoon chopped fresh cilantro (optional, up to 2 ); salt & fresh ground pepper (to taste)