1 Peel onion, cut in half, then into 6 or so thick segments
2 Warm a 10cm pool of olive oil in a heavy bottomed pan, add onions and cook for 3-4 minutes - crush or chop garlic
3 Add fennel seeds, bay leaf, garlic and sausages, brown lightly all over
4 Add passata and 1 tablespoon mustard, bring to boil and then put in drained and rinsed butter beans and S&P
5 Simmer for 20-25 minutes (I like to chop sausages up into 3 pieces after about 10 minutes - just to be sure they cook through)
6 Stir in last tablespoon of mustard and serve with a bit of green salad, a hunk of bread and a spicy wine.