Savory Puff Pastry Bites with Caramelized Onions and Mushrooms These savory puff pastry bites hit all the right notes with sweet caramelized onions, marinated Portobello mushrooms, Applewood smoked cheddar cheese, and a hint of fresh thyme. Although there are several steps required to assemble these tasty morsels, the results are well worth the effort!