Savory Spinach and Mushroom Breakfast Strata

Preheat oven to 350°F (175°C). Lightly grease an 8x8-inch baking dish.

Cut the sourdough bread into 1-inch cubes and spread them on a baking sheet. Toast in the oven for 10 minutes until lightly golden. Set aside.

In a large skillet, melt the butter over medium heat. Add the finely diced shallot and cook for 2-3 minutes until translucent.

Add the sliced mushrooms and minced garlic to the skillet. Cook for 5-7 minutes until the mushrooms have released their moisture and begun to brown.

Stir in the fresh thyme and cook for another minute until fragrant.

Add the spinach in batches, stirring until wilted. Season with a pinch of salt and pepper. Remove from heat and let cool slightly.

In a large bowl, whisk together the eggs, milk, heavy cream, dijon mustard, nutmeg, salt, and pepper until well combined.

Layer half of the toasted bread cubes in the prepared baking dish. Top with half of the mushroom-spinach mixture and 1/3 cup of the shredded gruyere.

Add the remaining bread cubes, followed by the remaining mushroom-spinach mixture. Pour the egg mixture evenly over the layers, pressing down gently to ensure the bread absorbs the liquid.

Cover with plastic wrap and refrigerate for at least 30 minutes (or overnight for best results).

Remove from refrigerator and let stand at room temperature for 15 minutes. Sprinkle the remaining 2/3 cup of gruyere on top and add halved cherry tomatoes.

Bake uncovered for 45-50 minutes, until the strata is puffed, golden brown, and a knife inserted in the center comes out clean.

Let stand for 10 minutes before serving. Garnish with chopped fresh chives.