Preheat oven to 180°C.
Cut new potatoes into quarters.
Place on baking tray with a little olive oil and place in oven for 15 minutes.
Cut sausages in half, cut onions in large chunks and cut Portobello mushrooms in quarters.
When potatoes are brown, add sausages, onions and mushrooms. Bake until brown, approx. 15 minutes.
Season with salt and pepper and fresh thyme.