Melt butter in a heavy saucepan over medium-low heat; whisk in flour until smooth. Cook, whisking constantly, 1 minute. Gradually whisk in milk; cook over medium heat, whisking constantly, 5 minutes or until thickened. Remove from heat, and whisk in remaining ingredients.
Cook sausage in a large nonstick skillet over medium-high heat, stirring until sausage crumbles and is no longer pink. Remove from pan; drain well, pressing between paper towels.
Melt butter in a large nonstick skillet over medium heat. Add green onions and cilantro, and sauté 1 minute. Add eggs, salt, and pepper, and cook, without stirring, until eggs begin to set on bottom. Draw a spatula across bottom of pan to form large curds. Continue to cook until eggs are thickened but still moist; do not stir constantly. Remove from heat, and gently fold in 1 1/2 cups Cheese Sauce and sausage.
Spoon about 1/3 cup egg mixture down the center of each flour tortilla; roll up. Place, seam side down, in a lightly greased 13- x- 9-inch baking dish. Pour remaining Cheese Sauce evenly over tortillas; sprinkle evenly with Monterey Jack cheese.
Bake at 350° for 30 minutes or until sauce is bubbly. Serve with desired toppings.
Note: Prepare half the cheese sauce recipe if you prefer a lighter breakfast.