Step 1In a large, heavy soup pot or Dutch oven heated over medium heat, add the olive oil, then the onions and a generous pinch of salt. Cook, stirring until tender, 6 to 8 mionutes. Stir in the garlic, jalapeños, olives and capers, and continue to cook just until the garlic is fragrant, another minute or so.
Step 2Add the tomatoes, cilantro sprigs, mint, oregano, bay leaves, and 1/2 teaspoon salt. Cook, stirring often, until the tomatoes are somewhat cooked down and the mixture smells fragrant, about 15 minutes.
Step 3Stir in the potatoes, winter squash and water, and bring to a simmer. Cook, stirring occasionally, until the potatoes and winter squash are tender, about 30 minutes. (The soup can be made ahead of time up to this point. Reheat before continuing.)
Step 4Shortly before serving, bring the soup back to a simmer. If cooking fish along with the crabmeat, add the fish and simmer for 5 minutes before adding the crabmeat. Stir in the crabmeat and heat (careful that the soup does not boil) until the crab is warmed through and the fish flakes easily, about 5 minutes. Taste and adjust the seasoning if desired.
Step 5Stir in the chopped cilantro, and serve the soup with lime wedges on the side.