Bring some water for the pasta to a boil over medium heat and salt it generously. Add the pasta and cook for about 10 minutes or as the package directs.
Warm a fairly wide, heavy-based saucepan over medium heat. Add the salami strips, not worrying if they clump together. Stir with a wooden spoon for 1 to 2 minutes.
Stir in the tomatoes and add about 1/2 a tomato can of water.
Stir in 1 tablespoon butter, then add the bouquet garni, if using, and the drained beans. Leave it to bubble away, firmly but gently, while the pasta finishes cooking.
Just before draining the pasta, remove and reserve a little of the cooking water.
Stir the drained pasta into the sauce, then remove from the heat, and stir in the remaining butter. If you think the sauce needs it, splash in some of the pasta cooking water, and stir again with a wooden spoon. Leave to stand for 2 minutes before serving, removing the bouquet garni, if used.