Preheat your oven to 350°F (180°C) and grease an 8-inch square baking dish with olive oil.

In a large skillet over medium heat, add olive oil and sauté the chopped Lacinato kale for about 2–3 minutes until wilted.

Incorporate the cremini mushrooms and diced yellow onion, seasoning with salt and black pepper. Cook for 3–5 minutes until onions are translucent.

In a separate bowl, whisk together eggs and milk until well combined and slightly frothy.

Layer slices of ciabatta bread in the prepared baking dish, followed by half of the sautéed kale, mushrooms, and onions, and sprinkle sharp cheddar cheese.

Repeat the layering process with another set of ciabatta slices, remaining sautéed vegetables, and more cheese.

Pour the egg and milk mixture over the layers, pressing down gently to soak the bread.

Cover the dish with foil and let it rest for about 15 minutes.

Bake the covered baking dish for 30 minutes, then uncover to bake for an additional 25-30 minutes until golden brown.

Allow the strata to cool for a few minutes before slicing and serving with a fresh salad or seasonal fruit.