Grain mustard, whole or halved shallots, smoked or Hungarian paprika, roasted peppers, creme fraiche. I also like aubergine, though I realise they are an acquired taste.
You could always serve it in a jacket potato if you arecckncerned about mushy potatoes.
I find sausages also go well with cheesy baked cabbage. Finely shredded cabbage...cook gently with sliced onion or shallots until just tender, season. Put in a baking dish with lots of grated cheddar...maybe some garlic and herb Boursin too...pour a bit of cream over. Bake until golden and bubbly.