al/en/en el desayuno?
The sentence (given by a native speaker) is: "Me gusta aplastar papas y comerlas como una sopa al desayuno" (I like to mash potatoes and eat them like a soup in/at breakfast)
I have 2 questions:
what is the correct word for "mash" in Spanish (used in Latin America, especially in Chile)? I've asked 3 native speakers, and they each have given me a different word, such as "aplastar", "moler", "mezclar"
should it be "al desayuno" or "en desayuno" or "en el desayuno"? Again, disagreement amongst the three native speakers I have asked.
Thanks.
2 Answers
"Cada loco con su tema" or "Different strokes for different folks.
Much of lexical difference is regional. The answer to your question is "yes" to all of the above. All the verbs you have given for "to mash" potatoes are valid. There is even one more "majar."
In Spain "papas" are "patatas." Other places will even have other names.
A tortilla in Spain is an omelette. In Mexico it's a flat pancake-like thing, made of flour, water and lard or oil that you fry up on both sides and eat it like bread or roll things up in it and call it a "burrito" or something similar. There are also the smaller tortillas made of corn which you can eat separately or make tacos out of them..
"Al desayuno to me has the meaning of "at breakfast" "en el desayuno" refers to what you eat "for breakfast' EX. "Me gusta comer tortillas de patatas en el desayuno."
Your native speakers aren't disagreeing, they're merely reflecting their regional preferences.

I would say:
Me gusta hacer puré de papas y comerlo como sopa en el desayuno.
But as Daniela said much of these differences are regional.