To make the relish, place the vinegar and sugar in a saucepan over low heat and stir until the sugar is dissolved. Add the beetroot, increase heat to medium and cook, stirring occasionally, for 15 minutes or until thickened. Set aside.

Place the beef, chorizo, salt and pepper in a food processor and process until well combined. Shape mixture into 4 patties. Preheat a char-grill pan or barbecue over high heat. Brush the patties with oil and cook for 4-5 minutes each side or until cooked through. Place the sour cream and horseradish in a bowl and mix to combine. Spread the rolls with the horseradish mixture and top with the patties, beetroot relish and baby spinach leaves to serve. Serves 4.

• If you prefer to slice the beetroot, you will need to decrease the cooking time for the relish by 2-3 minutes.