Learn Hardcore Japanese: watasitati ha hutatu no menyuu wo kuraberukoto ni simasita.

The particle は marks 私たち as the topic of the sentence. It tells the listener “we” is what this sentence is about. In many cases the topic and subject overlap, but は emphasizes the theme or context rather than grammatical subject alone.

Why do we say 二つのメニュー instead of 二つメニュー?

When you use the traditional Japanese counter つ with a noun, you need の to link them. The pattern is number + の + noun. So 二つのメニュー literally means “two of (the) menus.”

Why is メニュー written in katakana?

メニュー is a loanword (gairaigo) borrowed from French/English. Japanese convention is to write most foreign-origin words in katakana, so you see メニュー instead of hiragana or kanji.

Why do we use を after 二つのメニュー?

The particle を marks 二つのメニュー as the direct object of the verb 比べる (to compare). It shows what is being compared.

What is the role of こと in 比べることにしました?

Here こと nominalizes the verb 比べる, turning “to compare” into “the act of comparing.” It’s part of the verb-dictionary-form + ことにする grammar, which means “to decide to do (verb).”

What does ～ことにしました mean, and why is it in the past tense?

～ことにしました means “decided to (verb).” The past tense しました indicates that the decision has already been made. If you were announcing a decision right now, you might use ～ことにします (“I’ll decide to…”), but when reporting a decision you’ve made, you use ～ことにしました.

Could you just say 比べました instead of 比べることにしました? What’s the nuance difference?

比べました simply states “(we) compared.” It focuses on the action having taken place. 比べることにしました focuses on the decision: “(we) decided to compare.” One tells what you did, the other tells what you chose to do.

Is 私たち necessary here? Japanese often drops pronouns, right?

You’re correct—Japanese frequently omits pronouns when context makes the subject clear. Including 私たち with は adds clarity or emphasis (“as for us, we decided…”). If it’s obvious who the decision-makers are, you could drop 私たち　は and just say 二つのメニューを比べることにしました.