Preheat oven to 350 degrees.
In a medium skillet, cook the sausage until browned. Drain.
Heat olive oil in a large non-stick skillet over medium heat. Add the onions and garlic and cook until translucent. 3-5 minutes.
In a large bowl, whisk together the eggs, milk, salt and pepper.
Pour the eggs into the skillet with the onions and cook, stirring frequently, until eggs are thickened but not overdone.
Remove from heat and stir in sausage, green chilies and cheddar cheese. Season egg mixture, if needed.
In a medium bowl, whisk together the green enchilada sauce, cream and chili powder.
Lightly grease a 9×13 inch baking pan. Spread about 1/2 cup of the green enchilada/cream sauce on the bottom of the pan.
Spoon about 1/3 cup of the egg mixture into the center of a tortilla and roll. Place in pan, seam side down. Repeat until all of the filling has been used.
Pour the remaining sauce over the enchiladas and sprinkle the Monterey Jack cheese evenly over the top.
Cover with foil. If desired, enchiladas can be made to this point and refrigerated overnight before baking.
Bake for 15-20 minutes. Uncover and bake about 10 minutes more, or until sauce is bubbly and cheese is golden.
Top with optional toppings of choice (salsa, avocado, sour cream, cilantro).
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.