Soak peas in 4 cups of water for 4 hours or longer. In a medium saucepan, bring peas and soaking water to a boil. Add tomatoes. Simmer, covered, until peas are very soft, 20 to 25 minutes. In a blender or food processor, puree 2 cups of pea mixture until smooth, adding a little extra water if necessary. Return pureed peas to the saucepan. Cover and keep warm. In a large deep pot, combine onion, garlic,parsley, dill, sweet potatoes and remaining 2 cups water. Bring to a boil, reduce heat and simemr 6 to 7 minutes. Add broccoli and simmer another 6 to 8 minutes, or until broccoli is tender but still crunchy. Add pea mixture reduce heat to low, cover and cook gently until just heated through. Serve garnished with parsley. Serves 4. Per serving: 271 cal; 16 g prot; 1 g fat; 54 g carb; 0 chol; 38mg sod