Learn German: Sie haben hier so eine absurde Speisekarte!

This is a classic false friend! In German, die Speisekarte is the physical list of food options you read. The word das Menü actually refers to a set meal with multiple courses, not the menu card itself.

Why do we use so eine to mean "such an"?

In everyday spoken German, so ein or so eine (literally "so a") is the most natural way to say "such a". You might also see eine solche in formal writing, but so eine is much more common in conversation.

Why is the adjective ending on absurde just an "-e"?

The word Speisekarte is feminine, and it is the direct object of the verb haben, making it accusative. When following the article eine, a feminine adjective in the accusative case takes an -e ending.

Why does hier come before the object, unlike the English "such an absurd menu here"?

German word order usually places short adverbs like hier right after the conjugated verb. The longer, heavier direct object (so eine absurde Speisekarte) naturally falls to the end of the sentence.