In a large mixing bowl, combine the olive oil, peri peri sauce, tomato purée, lemon juice and water. Stir in the spices, seasonings and minced garlic, mixing thoroughly until everything is well combined.
Place the chicken legs and potato wedges into the bowl. Toss everything together until the chicken and potatoes are evenly coated in the marinade, making sure all sides are covered.
Cover the bowl and refrigerate for at least 2 hours to allow the flavours to develop. For the best results, leave to marinate overnight in the fridge.
Preheat the oven to 180°C. Arrange the marinated chicken and potato wedges on a large roasting tray in a single layer, spreading everything out evenly. Pour any remaining marinade over the chicken and potatoes.
Place the tray in the preheated oven and roast for 30 minutes, allowing the chicken to begin browning and the potatoes to soften.
Carefully remove the tray from the oven. Turn the chicken legs over and flip the potato wedges to ensure everything cooks evenly. Spoon some of the juices from the tray over the chicken to keep it moist.
Return the tray to the oven and roast for another 25–30 minutes, or until the chicken is cooked through. The potato wedges should be tender inside and golden around the edges.
Remove the tray from the oven and leave the chicken to rest for 5 minutes before serving.
