Preheat oven to 400 degrees F. Coat a large, rimmed baking sheet with cooking spray. Spread the bread cubes in a single layer and bake about 12-15 minutes, tossing halfway through. Bread should be crispy on the outside and still slightly soft on the inside.

Meanwhile, heat a large saucepan over medium-high heat. Add sausage and saute, breaking up sausage with a wooden spoon, until browned and just cooked through, about 3-5 minutes. Transfer sausage to another dish and set aside.

Add the onions, garlic, rosemary, and thyme to the leftover sausage grease and lower heat to medium. Saute until onions are soft, about 5 minutes. Add half the Swiss chard or kale and saute until wilted. When there is room in the saucepan, add the remaining chard and saute until wilted.

Turn off the heat. Add bread, turkey sausage, and dates to the onion and chard/kale mixture and mix well.

In a large bowl, whisk milk and eggs together until frothy. Prepare a 9x13-inch baking dish with cooking spray. Sprinkle about ¼ cup cheese evenly over the bottom of the dish. Layer with ½ of the bread and vegetable mixture, another ¼ cup cheese, the rest of the bread and vegetable mixture, and another ¼ cup cheese. Pour the milk & egg mixture over the entire dish and sprinkle with remaining cheese. Let sit about 15 minutes.

Cover the dish with foil and bake at 400 degrees F for 30 minutes. Remove the foil and bake an additional 15 to 20 minutes until the milk and egg mixture is cooked through and no longer runny. The top of the dish should be toasted, but not burnt.

Let cool about 5 minutes before serving.