Make the sauce first - In a large saucepan over medium heat, add oil and flour and whisk together to make a past, cooking for 1 minute. Pour in other red sauce, chicken broth, salt, and pepper, and bring to a boil. Reduce heat and simmer 30 to 45 minutes.
Meat- Brown meat with onions in a skillet. Drain off fat. Stir in 2 cans diced green chilies and seasoned salt. Set aside.
Preheat oven to 350.
Tortillas - Heat canola oil in a small skillet over medium heat. One by one, using tongs, fry tortillas oil until soft, not crisp—about 30 seconds per side. Remove to a paper-towel lined plate. Repeat until all tortillas have been fried.
Assembly - Pour ½ cup red sauce in bottom of baking pan. Spread to even out. Dip each tortilla into red sauce, then remove to work surface. Spoon meat, a little grated cheese, a little black olives, and green onions in the center of tortilla. Roll up and place, seam down, in baking pan. Repeat until pan is filled. Pour extra red sauce over enchiladas. Top with remaining cheddar cheese.
Bake for 20 minutes or until bubble. Sprinkle chopped cilantro over enchiladas before serving.