Coarsely chop the broccoli and thinly slice the shallots. In a large saucepan, combine the broccoli, olive oil, shallots, garlic and kombu. Season with 2 teaspoons of the salt, then add just enough water to cover, about 6 to 8 cups. Bring to a boil, then reduce the heat to a gentle simmer. Cook until the broccoli is very tender, about 20 minutes. Remove the pot from the heat and discard the kombu. Add the remaining 1 teaspoon salt and the herbs, then blend with an immersion blender until smooth. Taste and adjust the seasoning with more salt. Ladle into bowls, drizzle with more olive oil and serve with lemon wedges for squeezing over.