Me, I take a slice of white sandwich bread, slather it with a good smear of Miracle
Whip, put on one slice of
bologna, a leaf of ice burg lettuce and top with another slice of sandwich bread.
Read labels on everything you might want to eat, looking for milk, butter, dried milk, yogurt, cheese, casein, whey, sodium caseinate, lactose (and other things that start with «lact», although sodium lactylate is non-dairy)... Read all labels — check the bread, check the hot dogs and
bologna, check things that say «non-dairy» like non-dairy creamer and Cool
Whip (as mentioned above, these both contain dairy).