Preheat the grill or oven to 375F.
In a large baking dish, pour about 1/2 cup of the roasted green enchilada sauce. (Enough to cover the bottom of the baking dish.)
Fill your tortillas with brisket, a bit of Monterey Jack Cheese, some bell peppers, and roasted onions.
Roll and place seam side down in the baking dish.
Continue to fill and roll tortillas until you have filled the baking dish. They can be snug in the dish so they keep their shape.
Top with 1-2 cups of the roasted green enchilada sauce, and cover with Monterey Jack, as desired. Sprinkle with remaining peppers and onions, and Meat Church Holy Cow seasoning.
You can cover the enchiladas with foil and refrigerate until ready to cook, or proceed.
From cold, cook enchiladas covered for 25-30 minutes, then proceed. If your brisket filling is warm or room temp, skip this step.
Cook uncovered about 20-25 minutes, until the cheese is melted and sauce is bubbling.