To make your own spice:
Combine all ingredients and mix well. Store in a jar with a tight fitting lid.
Preheat the oven to 400 degrees F. Place the bagel cubes on a large sheet pan and toast in the oven for about 10 minutes, or until golden brown.
In a skillet, break up and brown the sausage until cooked through.
Butter a 9 by 13 inch baking dish.
Put the cooked sausage in the baking dish and spread it out evenly.
In a large bowl, whisk together the eggs, milk, red onion, capers, dijon, basil and cheddar. Season with salt and mix to combine. Stir in the toasted bagel cubes and pour the mixture into the prepared baking dish. Dot with the cream cheese cubes (pressing some down to submerge). Cover tightly with tin foil and let sit for a few hours in the refrigerator. This is best if you can make it the night before and let it sit overnight.
When ready to bake, preheat the oven to 350 degrees F. Let casserole sit at room temperature while the oven preheats. Place covered casserole in the oven and bake for 35 minutes. Uncover and continue to bake for an additional 20 minutes, or until the center is set.
Garnish with chives and a healthy sprinkle of homemade everything bagel spice.