Preheat oven to 400 degrees F.
Combine the chicken, drained Ro-Tel tomatoes, 1 cup Monterey Jack cheese, all of the cheddar cheese, and all-purpose seasoning in a large mixing bowl. Set aside.
Melt butter in a medium saucepan. Whisk in the flour to make a roux, stir and cook until bubbly then slowly add the chicken broth, whisking constantly, until smooth and thickened. Bring to a low boil, whisking frequently. Whisk in the cumin, coriander, salt and a little freshly ground black pepper. Remove the pan from the heat and stir in the sour cream and green chiles.
Add ½ cup of the sour cream sauce to the chicken mixture and toss to combine well.
Add a scant 1 cup of sauce to the bottom of the baking dish and spread it around. Divide the chicken mixture evenly between tortillas (about ½ cup per tortilla). Roll them up and place them seam-side down in the baking dish. Pour the remaining sauce evenly over enchiladas. Top with the remaining Monterey Jack cheese.
Cover the dish with foil and bake for 15 minutes. Remove the foil and continue to bake for an additional 5 to 10 minutes, or until the sauce is bubbly and cheese has melted. Remove the pan from the oven and let it rest for 5 minutes.
Garnish with green onions and cilantro and serve with chopped tomatoes, sliced avocado, and hot sauce (optional).