Preheat your oven to 200° Celsius.
Add your olive oil to an oven dish along with your onion and fresh chilli (if using).
Now add your chilli flakes & garlic and spread around the surface of your oven dish.
Place on the top shelf of your oven to heat for 15 minutes.
After 15 minutes, remove your oven dish from the oven and add your tin of tomatoes, vinegar, sugar, cumin, kekik (thyme or oregano - or both), salt & pepper.
Stir around to mix together and return to the oven.
Leave for around 10 minutes until the sauce starts to bubble.
Once the sauce is bubbling away in the oven, start to fry your köfte separately by heating your oil in a frying pan on a high heat.
Fry your köfte without turning too often (to avoid breaking them up) until they are brown on all sides. This takes around 5-10 minutes.
Once your meatballs have browned on all sides, remove your sauce from the oven and arrange them in the sauce.
Spoon a bit of the tomato sauce over the köfte and return the dish to the oven.
Meanwhile, bring a pan of water to the boil.
When the water is boiling, add your potatoes.
Boil for around 7-10 minutes so that the potatoes are just starting to soften.
Now remove your dish from the oven and turn the köfte.
Increase the oven temperature to 220 degrees Celsius.
Drain your potatoes and arrange them around your meatballs.
Return to the oven for around 10 mins until your potatoes start to bake on top.
After 10 minutes, add your peppers and arrange between the meatballs and potatoes.
Turn your oven to high for the last 15 minutes to really get everything sizzling hot.
Remove from the oven and leave to stand for a couple of minutes before serving.