1.Prepare your vegetables. Chop 1 large onion into small dice, about 5mm square. The easiest way to do this is to cut the onion in half from root to tip, peel it and slice each half into thick matchsticks lengthways, not quite cutting all the way to the root end so they are still held together. Slice across the matchsticks into neat dice. Cut 1 red pepper in half lengthways, remove stalk and wash the seeds away, then chop. Peel and finely chop 2 garlic cloves.
2.Start cooking. Put your pan on the hob over a medium heat. Add the oil and leave it for 1-2 minutes until hot (a little longer for an electric hob). Add the onions and cook, stirring fairly frequently, for about 5 minutes, or until the onions are soft, squidgy and slightly translucent. Tip in the garlic, red pepper, 1 heaped tsp hot chilli powder or 1 level tbsp mild chilli powder, 1 tsp paprika and 1 tsp ground cumin. Give it a good stir, then leave it to cook for another 5 minutes, stirring occasionally.
3.Brown the 500g lean minced beef. Turn the heat up a bit, add the meat to the pan and break it up with your spoon or spatula. The mix should sizzle a bit when you add the mince. Keep stirring and prodding for at least 5 minutes, until all the mince is in uniform, mince-sized lumps and there are no more pink bits. Make sure you keep the heat hot enough for the meat to fry and become brown, rather than just stew.
4.Making the sauce. Crumble 1 beef stock cube into 300ml hot water. Pour this into the pan with the mince mixture. Open 1 can of chopped tomatoes (400g can) and add these as well. Tip in ½ tsp dried marjoram and 1 tsp sugar, if using (see tip at the bottom), and add a good shake of salt and pepper. Squirt in about 2 tbsp tomato purée and stir the sauce well.
5.Simmer it gently. Bring the whole thing to the boil, give it a good stir and put a lid on the pan. Turn down the heat until it is gently bubbling and leave it for 20 minutes. You should check on the pan occasionally to stir