Peel and coarsely chop onion and garlic. Wash the sweet red pepper and chilli pepper, remove the core, and roughly chop into bite-sized pieces as well. Add onion, garlic, sweet pepper and chili pepper to a blender or food processor and blend.
Transfer the marinade mixture to a casserole dish, then stir in the spices and set aside. Pat dry chicken quarters with paper towels and separate them into thighs and drumsticks.
Using the tip of the knife, prick the meat for the marinade to penetrate better and deeper into the meat. Next peel, wash and cut the potatoes into wedges.
Add the chicken and potatoes to a casserole dish with the marinade. Using your hands coat the chicken and wedges with marinade evenly. *Feel free to use a mixing bowl with a cover or resealable plastic bag if you don’t want to get your hands dirty.
Cover with cling film and chill for at least 1 hour or overnight. About 10 minutes before cooking take the casserole dish out of the fridge to bring it to room temperature and preheat oven to 200 °C (392 °F), with both top and bottom heat.
After transfer the chicken and potatoes to a large baking sheet (baking tray) lined with parchment paper or aluminum foil and bake for about 45 minutes. Turn the chicken and potatoes halfway. In the meantime, make the dipping sauce
To make the sauce, simply pour about 250 ml (1 cup) water into the casserole dish with the leftover marinade and mix well, while scrapping up all the marinade from all side with a spatula.
Pour the marinade mixture into a saucepan or small pot. Add sugar, sunflower oil, tomato paste and combine well. Bring to a boil and let cook for about 15 minutes. Keep stirring in between so that it doesn’t burn at the bottom. Season with salt and pepper if necessary and remove from the heat.
After 45 minutes, transfer the potatoes onto a serving platter. Put the baking sheet with chicken back into the oven, turn the oven to grill setting and grill the chicken for about 10 minutes. Keep a close eye on the meat, so that it won’t burn.
Serve the chicken and potatoes with dipping sauce and enjoy.