Collard-Artichoke-and-Mushroom Strata

A strata is essentially a cross between a bread pudding and a casserole; there are many sweet stratas but it's the savory stratas that steal our hearts. The prep work can be done the day before or let sit for an hour before baking to soak up all the goodness. This can be a main dish or served as a side dish. I'm planning on making it for Easter Brunch.

1 (12-oz.) rustic baguette, cut into 1-inch cubes (about 8 cups)
3 tablespoons unsalted butter, plus more for greasing baking dish
1 up chopped sweet onion (from 1 small onion)
1 (8-oz.) pkg. sliced fresh button mushrooms
6 cups chopped stemmed collard greens (from 1 [11-oz.] bunch)
1 teaspoon kosher salt, divided
1 teaspoon black pepper, divided
2 cups coarsely chopped thawed frozen artichoke hearts (about 8 oz.)
8 large eggs
2 cups half-and-half
1 (5.2-oz.) container garlic-and-herb spreadable cheese (such as Boursin)
8 ounces Swiss cheese, shredded (about 2 cups), divided

Preheat oven to 375°F. Arrange bread pieces in a single layer on a large rimmed baking sheet. Bake 10 minutes. Turn off oven; let bread stand in oven until crisp and dry on the outside and chewy on the inside, 5 minutes.

Meanwhile, melt butter in a large skillet over medium. Add onion and mushrooms. Cook, stirring occasionally, until onion is slightly softened, about 4 minutes. Add collards and ½ teaspoon each of the salt and pepper. Cover and cook, stirring occasionally, until collards are wilted, about 5 minutes. Stir in artichoke hearts; cover and cook 3 minutes. Uncover; let cool slightly, about 5 minutes.

Whisk eggs
in a large bowl until lightly beaten. Add half-and-half, spreadable cheese, 1 cup of the Swiss cheese, and remaining ½ teaspoon each salt and pepper. Whisk until well blended. Add toasted bread and collard mixture; toss well to combine. Spoon into a 13- x 9-inch baking dish greased with butter. Sprinkle evenly with remaining 1 cup Swiss cheese. Cover with aluminum foil; chill at least 7 hours or up to 12 hours.

Preheat oven to 350°F. Let the casserole stand at room temperature 30 minutes. Uncover; bake until cheese is browned in spots and filling is set, about 45 minutes. Let stand 5 minutes before serving.