In a large heavy saucepan bring 3 quarts water to a boil over high heat. Reduce the heat to medium-low, and add the favas and 2 teaspoons of the salt. Cover and simmer until the beans are tender, about 1 1/2 hours. Drain in a colander and set aside until ready to use.

In a heavy large saucepan heat the olive oil over medium-high heat. Add the bay leaves, crushed red pepper flakes, and the remaining 1 teaspoon salt and heat for 1 minute, stirring occasionally. Add the onions and bell peppers and cook, stirring occasionally, until softened, about 5 minutes. Stir in the parsley and garlic and cook, stirring, until fragrant, about 1 minute. Stir in the tomato paste and 7 1/2 cups water. Bring to a boil over high heat. Reduce the heat to medium-low and simmer until slightly thickened, about 30 minutes.

Add the fava beans and continue simmering until the beans are tender, about 1 hour. Toss with andouille or chorizo. Serve immediately, or cool, cover, and refrigerate for up to 3 days.