ACTIVE TIME 45 MINUTES TOTAL TIME 2 HOURS, 45 MINUTES SERVES 8
1 8-oz. bunch Swiss chard, trimmed2 Tbsp. olive oil8 oz. mixed mushrooms, sliced (about 3 cups)1 cup chopped yellow onion (from 1 onion)1 Tbsp. sliced garlic (from about 3 cloves)1 Tbsp. roughly chopped fresh thyme leaves, plus more for garnish2 tsp. kosher salt, divided1 16-oz. loaf stale crusty bread, torn into bite-size pieces (about 12 cups)Cooking spray4 oz. Gruyère cheese, shredded (about 1 cup), divided8 large eggs2½ cups whole milk1½ Tbsp. Dijon mustard
SEPARATE chard leaves from stems. Roughly chop leaves and stems.
HEAT oil in a large skillet over medium-high. Add mushrooms; cook, stirring occasionally, until browned, about 8 minutes. Add onion, garlic, thyme, chard stems, and ½ teaspoon salt; cook over medium, stirring occasionally, until onion…
