Heat the oil in a pan and fry the onion and garlic until soft.
Add the sausages and fry until lightly browned.
Add the drained beans, cherry tomatoes and mixed herbs and simmer for 3 minutes.
Season to taste.
Pour the mixture into an oven proof dish and top with the mash, spread or piped over.
Bake at 180C until the mash is light golden.