Spiced bean stew with sausage

4 tbsp olive oil

6–8 sausages

1 red onion, chopped finely

3 garlic cloves, peeled, bruised but left intact

1 red chilli, deseeded and chopped finely

150g pancetta/bacon lardons (optional)

1 bunch of thyme, rosemary or both

1 tin cannellini beans

2 tins tomatoes

1 glass red wine

1 tsp sugar

basil leaves, to serve

salt 

black pepper