White Sauce: In a small saucepan over a medium heat melt butter or margarine and blend in all flour with a pinch of salt and pepper. Cook and stir for around one minute until darkened ever so slightly.
Stir in small quantities of milk at a time allowing the mixture to boil before adding the next amount of milk. When all the milk is added you should have a creamy white sauce. Remove from the heat.
When the white sauce has cooled slightly, gently stir in the yoghurt and half the grated cheddar then set aside.
Meat Sauce: Brown the onion, capsicum and mince in a frypan over a moderate heat. Once lightly coloured drain any excess fat from the pan. If adding any alcohol do so now and let cook out until dry.
Add garlic, cumin, mixed herbs, sugar, tomato puree, kidney beans, salt and pepper to the beef mixture and stir over a gentle heat for several minutes until reduced slightly.
Add small amounts of chilli at a time stirring well and tasting between each addition until the desired heat is achieved.
Assembly: In a family sized lasagne dish layer half the chips, half the chilli mix then half the white sauce. Repeat with the remaining mixtures. Ensure the top white sauce layer covers the other ingredients.
Sprinkle the top with the remainder of the cheese and a little salt and pepper.