Broaden your mind, you can always use the ingredients for a snack or the next days meal. The pepper for example you could make a nice salad using it for lunch the next day or the egg whites to make a meringue for desert (pavlova, eton mess etc) or if it's the yolk use it for some holindaise sauce and make some eggs benedict for breakfast the next morning.
Or you could do some basic maths and round up your ingredients, whatever you don't use then freeze it or have it the next night aswell.
Or you could do some basic maths and round up your ingredients, whatever you don't use then freeze it or have it the next night aswell.