TASK DEFINITION: Given the background description of some cooking related query, summarize the question into a title
PROBLEM: Many commercial cake mixes use vegetable oil, but I have seen some (usually 10% or less of what the store carries) that are "Butter Recipe".These use butter instead of vegetable oil. What is the difference in these? And is the reason you do not find many in stores is because it is not popular, or costs more, or something else?

SOLUTION: What is the difference between regular (vege. oil) and butter recipe cake mixes?

PROBLEM: When making e.g. spaghetti sauce, do I:first sweat the onions and then add the minced meat?first brown the minced meat and then add the onions?do both at the same time but in different pans and add them together afterwards?What are the advantages of preferring one of the options over the others?

SOLUTION: First onion or first minced meat?

PROBLEM: My wife's chicken cake recipe calls for mayonnaise as one of the batter ingredients. In my opinion, mayonnaise is completely unsuitable for high-temperature processing (as in baking), but I was unable to come up with a substitute for it.So, my question is, what can we put into cake batter instead of mayonnaise?Update: I think mayonnaise is unsuitable for baking because it is an emulsion which separates into its ingredients when heated, emulsifying agents used in a commercial mayo are not particularly healthy, and mayonnaise does not taste any good when it is broken into its components.The components of the batter are: 6 table spoons of flour, 3 eggs, 200gram mayo, 200gram sour cream. The components of the filling are: chopped prepared chicken meat, chopped sauteed onions, boiled eggs, etc.

SOLUTION:
Mayonnaise substitute in cake batter