Dice the bacon. Heat a large pot or Dutch oven over medium heat.
Add the finely chopped bacon and fry it until crisp and most of the fat is rendered.
Peel the onion and cut it into small dice.
Once the bacon is fried, add the onion. Sautee it until it is translucent and soft. Add a lot of broth or water (if using the bouillon), the dry or soaked peas, and the bay leaf. Bring to a soft boil and cook for 15 mins.
In the meantime, peel and chop the remaining vegetables. After 15 minutes, add the chopped vegetables, bring back to a boil, and cook for another 30 minutes or until the peas are soft.
Season to taste with salt and pepper.
Turn off the heat and add the sausages. You don't want to cook them but just heat them up.