Sentence:  But her favorite way to express their simplicity is to <WSD>shirr</WSD> them. It's an old-fashioned technique that essentially means baking an egg. In her version, the eggs in ramekins are simmered in seasoned cream that reduces slightly into a soft sauce. 
Meaning of the word marked with <WSD> tags:  To bake (a raw egg removed from its shell) in a baking dish.