In a large skillet over medium-high heat, cook turkey sausage in oil for 4-5 minutes. Reduce heat to medium and add as much kale as will fit. Continue to cook and add more kale as there is room until kale has wilted and is bright green. Place the cubes of bread in a prepared 3 quart or 9 inch x 13 inch baking dish and top with the cooked kale mixture. In a large bowl, scramble the eggs; whisk in milk, mustard, salt and pepper and stir in cheese. Pour over kale mixture; cover and refrigerate for 1 hour. Heat oven to 350 F. Bake for 40 - 45 minutes until golden brown and set around the edges but slightly wobbly in the center. Cool for 15 minutes before serving.