Preheat oven to 400 degrees.
Line a large baking sheet (with sides) with several sheets of foil and drizzle with a bit of oil. Spread the oil out over the pan. Set aside.
Put the sausage rounds, onions and potatoes into a large bowl. Drizzle with a couple tablespoons of olive oil and season to taste with salt, pepper, paprika and dried thyme. Toss together until everything is evenly distributed.
Pour out onto the baking tray and spread it out evenly. Place into heated oven and roast for 45 – 60 minutes, stirring every 15 minutes, until potatoes are golden brown and tender.
Turn off the oven. Sprinkle the cheese over the meat and potatoes. Return to oven for a few minutes to melt cheese. Serve immediately.