Brown the sausages in olive oil for 5–7 minutes. Remove and set aside.
Soften the onion in the same pan for 3–4 minutes. Add the garlic and cook for 1 minute.
Add the chopped tomatoes, tomato purée, Worcestershire sauce, Dijon, honey, smoked paprika, herbs and stock. Season and stir.
Add the haricot beans to the slow cooker and pour over the tomato sauce.
Nestle the sausages into the beans.
Cook on LOW for 7–8 hours or HIGH for 4–5 hours.
Towards the end of cooking, boil the potatoes for 15–20 minutes until tender. Drain and mash with butter and milk. Season.
Transfer the sausage and bean mixture to an ovenproof dish.
Top with the mashed potato and sprinkle over the grated cheddar.
Grill for 5–10 minutes, until bubbling and golden.
Serve hot with your favourite green vegetables and enjoy this proper bowl-of-comfort kind of dinner.