For the marinade, put the 150ml /1/4pint of Rubicon watermelon juice drink and olive oil in a shallow dish (not a metal one). Thinly slice half the red onion (reserve the rest for the salsa) and add it to the marinade with the garlic, coriander and mint
Add the lamb cutlets to the marinade, turning them to coat. Cover and chill for at least 30 minutes, turning occasionally
When ready to eat, put the potatoes on to cook in plenty of lightly salted boiling water
Preheat the grill. Grill the lamb cutlets for 4-5 minutes per side, or according to preference
Meanwhile, make the salsa by mixing together the Rubicon watermelon juice drink with the remaining red onion (finely chopped), watermelon, cucumber and mint. Season with a pinch of salt, pepper and sugar. Serve with the lamb cutlets and potatoes
Use the salsa to serve with fish or chicken instead of lamb – it’s delicious!