Creating Everything Bagel Breakfast Strata is easier than you might think. Follow these step-by-step instructions to make this incredible dish:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking dish.
2. Prepare Bagels: In a large bowl, add the cut-up everything bagels. Set aside.
3. Mix Eggs and Milk: In another bowl, whisk together the eggs and whole milk until well combined.
4. Add Seasoning: Stir in the everything bagel seasoning, salt, and pepper to the egg mixture.
5. Combine Ingredients: Pour the egg mixture over the bagel cubes. Gently fold in the cheddar cheese, diced ham, spinach, and onion.
6. Let It Rest: Allow the mixture to sit for at least 30 minutes, or overnight in the refrigerator. This helps the bagels soak up the egg mixture.
7. Bake the Strata: Pour the mixture into the greased baking dish and smooth out the top. Place in the preheated oven and bake for 35-40 minutes, or until the top is golden brown and the eggs are set.
8. Cool Slightly: After baking, let it cool for about 10 minutes before slicing into squares.
9. Garnish: If desired, sprinkle freshly chopped chives on top for an extra burst of freshness.

These clear steps allow anyone to create a delicious Everything Bagel Breakfast Strata with minimal fuss!