The most useful of all the techniques I have learned is how to use a combination of stock and 1 calorie spray oil in place of larger quantities of oil, butter or ghee.
With many dishes the first thing you do is soften onions, cook spices or brown meat using oil or it’s equivalent.
What I have found works very well in its place is starting with a few squirts of 1 calorie spray (any flavour) and use this until things start to catch or are at frisk if burning.
At this point use stock that suits the final meal (beef, fish, chicken, vegetable) to to keep the food cooking until it has reached the required level of cooking.
You then cook as you would normally. This is great for curries, stews, soups etc.
Also to avoid using flour as a thickener purée half the onion your are using and the. Add this to thicken the sauce. It works a treat.
The flavour will be a little different in that the oil/fat content is much lower but a good use of spices and herbs brings back the wow factor.