How to return random item that matches a criteria?

Worked through all the lessons but still lost.

In it’s simplest form, a user would select a category from a dropdown and hit submit. The app would then return a random item from a list that matches the category.

As an example, a list of restaurants, categorised by cuisine. If the user selects ‘Italian’ on the dropdown and hits submit, I’d like the app to load a page showing an Italian restaurant from a list I have.

Any help or pointers would be fantastic!