Saucepan sausage stew with fennel and lentils

dash of rapeseed oil

400g good quality banger style sausages, chopped into bite size pieces 

2 onions, finely chopped 

4 garlic cloves, finely chopped 

1 medium sized fennel bulb, sliced 

2 tsp fennel seeds, toasted 

1 tsp chilli flakes 

200g puy lentils 

300ml stock 

100ml white wine