Scraping Recipes with Nokogiri

Most of you probably know Nokogiri as the point in your Ruby on Rails install where you take a break to get a beverage. (Why is Nokogiri bundled with every flavor of Rails on Earth? I have no idea.* It's quite large, and specialized.) But here you are, already on a first-name basis with a world-class web scraper. Want to keep tabs on something that doesn't have an RSS feed? Aggregate content from a whole category of sites? Amass training data for your latest NLP project? You've come to the right place.