In a 6-quart soup pot, heat the oil over medium heat until smoking. Add the onion, garlic, hot pepper, and fennel and cook until soft and light golden brown, 8 to 10 minutes.
Add the tomatoes, wine and water, and bring to a boil. Lower the heat and simmer 10 minutes. Add the shrimp and simmer until cooked through, about 5 minutes. Pour into a bowl and garnish with fennel fronds and parsley.
Recipe adapted from Mario Batali