input question: buttermilk substitution

output answer: add vinegar or lemon juice to an equal amount of milk. let stand.

input question: Make pop corn.

output answer: Heat oil in a pan and add some kernels of corn. cook until it begins to pop, cover and finish.

input question: how to line a baking pan with parchment

output answer:
open the box, and pull the parchment to the desired length, tear off, and place on baking sheet.