Preparation Melt butter in a large saucepan over medium heat. Cook shallot and rosemary, stirring often, until shallot is starting to turn golden, about 4 minutes. Add cranberries, figs, brown sugar, vinegar, 1/2 tsp. salt, and red pepper flakes and increase heat to medium-high. Bring to a boil, stirring to dissolve sugar, and cook, stirring often and reducing heat as needed to avoid scorching, until cranberries burst, juices are syrupy, and pan is visible when a wooden spoon is dragged across the bottom, 9–12 minutes. Let cool. Taste and season with more salt if needed. Do Ahead Sauce can be made 1 week ahead. Cover and chill.
Preparation Melt butter in a large saucepan over medium heat. Cook shallot and rosemary, stirring often, until shallot is starting to turn golden, about 4 minutes. Add cranberries, figs, brown sugar, vinegar, 1/2 tsp. salt, and red pepper flakes and increase heat to medium-high. Bring to a boil, stirring to dissolve sugar, and cook, stirring often and reducing heat as needed to avoid scorching, until cranberries burst, juices are syrupy, and pan is visible when a wooden spoon is dragged across the bottom, 9–12 minutes. Let cool. Taste and season with more salt if needed. Do Ahead Sauce can be made 1 week ahead. Cover and chill.