1. Head the olive oil in a large casserole of deep pan over a medium heat. Add in your sausages and cook for around 8 minutes. Keep turning them to ensure they brown all over. Remove from the pan and set aside keeping your pan over the heat.
2. Add in your onions, celery, carrots and bacon and cook for 8 minutes until the onion and celery has softened and the bacon has started to crisp up.
3. Stir in your flour and the tomato purée and then pour in the Guinness and bring to the boil then cook for around 3 minutes until the Guinness has reduced down then pour in the stock and bring back to the boil.
4. Turn down to a simmer then add in the thyme, the sausages and the mushrooms and the beans if using and simmer for around 5 minutes giving it a stir every so often then season to taste and check it taste delicious. Finally cook it for 10 minutes until the sausages are cooked through and the sauce has thickened.
5. Serve it up with mashed potato or even rice, just see what you have in the cupboard.