Is there anything better than a great ham and cheese sandwich? Well, if there ever was a contender, I'd say it'd be this recipe for Croque Monsieur Savory Bread Pudding. Or Strata. Or whatever the heck you want to call it. This recipe is basically a giant deconstructed Croque Monsieur (aka ham, cheese, French Bread, and all things delicious).
Sauté The Onions: Coat a 2-quart (about 11-by-7-inch) baking dish with butter and set aside. Place a large frying pan over medium heat and add butter. When it foams, add onion, season with salt, stir, and cook until just softened about 3 to 4 minutes.Add garlic, season with salt and pepper, and cook until beginning to soften and fragrant, about 1 minute. Remove from heat and stir in thyme. TIP: Onions can be cooked up to two days ahead. Store refrigerated in an airtight container until ready to use.
Make The Bread Pudding Custard: Whisk eggs, half-and-half, mustard, hot sauce, and salt in a large bowl until evenly combined. Arrange half of the bread at the bottom of the prepared dish. Sprinkle with 1 cup of the Gruyère and half each onion mix and ham.Repeat layering with remaining bread, onion mixture, ham, and Gruyère cheese. Pour egg mixture over the top.
Push to ensure bread is submerged in egg custard, cover with plastic wrap, put a plate and a 1-pound weight on top (a large can of tomatoes or rice in a re-sealable plastic bag works well) place in refrigerator for 3 to 12 hours.TIP: Make bread pudding through this step up to the night before your dinner and then cook it in the morning.
Bake The Bread Pudding: When ready to bake, heat the oven to 325°F and arrange the rack in the middle. Let strata sit at room temperature while the oven heats, for at least 20 minutes.Bake for 20 minutes, then increase the temperature to 375°F. Sprinkle parmesan over the strata and bake for another 15 to 20 minutes until puffed and the edges pull away slightly. Remove from oven and sprinkle over remaining thyme.Cool for at least 5 minutes before serving. Serve with hot sauce on the side.TIP: Bread pudding can be baked up to three days ahead of time then stored covered in the refrigerator. Rewarm it in a low oven (about 200°F) until warmed through, about 30 minutes.