Peel the onions, slice them thinly. Gently sauté them in olive oil on the hotplate until they’re lightly brown, then add the cumin, tomato sauce and allow to caramelise.
Grill the sausages and bread on the barbecue grill. Spread the caramelised onions on the buns, place the sausages on top, cover with the other half of the bun. Watch out for falling onions!