You buy in mashed potatoes? Really?
Look, even my kids will tell you that I am a lousy cook.
But mashed potatoes?
Take some potatoes. Don’t bother to peel them or anything. Washing is optional - you are going to boil the suckers anyway.
Do get rid of the green bits. They will give you the trots.
Throw them in a pot.
Put a fire under it.
When they get mushy, hit them with a hammar, a K-Bar, a tanker bar, whatever is handy. We have an old tire iron for the chore.
Toss in butter,garlic, and cream.
Serve hot.
After the bragging in the TV commercials, we tried it out of curiosity. Horrible. Absolutely nothing like homemade. YMOV (your mileage obviously varies)