1. The day before you plan to serve your bake, cut your English muffins into cubes. Spread on a baking sheet and broil in the oven for a few minutes to brown them lightly.
2. Generously butter (2 tablespoons) a 9x13 casserole dish and spread the toasted English muffin cubes into the bottom of the dish.
3. Heat a non-stick skillet over medium-high heat and melt the remaining tablespoon of butter in the skillet. Sauté the ham and green onions for about 8 minutes, stirring occasionally, until the ham is starting to brown.
4. Layer the cooked ham and green onions on top of the English muffins.
5. Top the ham layer evenly with the shredded cheddar cheese.
6. Whisk together the eggs, milk, sour cream, mustard, salt and cayenne and evenly pour the mixture over the rest of the bake ingredients.
7. Cover the dish with foil and refrigerate overnight.
8. Remove the dish from the refrigerator about an hour before you plan to bake it the next day.
9. Preheat the oven to 375 degrees.
10. Bake the casserole for 30 minutes, covered with foil.
11. Remove the foil and continue to bake for another 15 - 20 minutes, or until the dish is looking puffed and the top is browning.
12. While the casserole is baking place the egg yolks, lemon juice and salt in a blender. Blend on high for a few seconds. Set the blender to low and through the hole in the middle of your blender lid, pour the melted butter in a slow steam into the egg yolk mixture. Cover the hole and blend the hollandaise on high speed for about 1 minute. Taste, add a little more lemon and salt if needed, and serve immediately with the breakfast bake.
13. Top the Eggs Benedict breakfast bake with the hollandaise sauce and chopped fresh chives