Preheat the oven to 375°F and lightly spray both a 9x13-inch and a 9x9-inch casserole dish with cooking spray.
Spread 1/2 cup salsa verde in the bottom of the 9x13-inch dish and 1/4 cup salsa verde in the bottom of the 9x9-inch dish.
Make the filling: in a large bowl combine 3/4 cup salsa verde, the shredded chicken, 2 cups shredded Monterey Jack, 1 cup crumbled queso fresco, sour cream, onion powder, garlic powder, oregano, cumin, salt, chili powder, and black pepper; stir until evenly mixed.
Assemble enchiladas: place about 1/2 cup of the chicken mixture along the bottom half of a tortilla, roll it up tightly, and place seam-side down in one of the prepared dishes; repeat until you have 10 enchiladas (6 in the 9x13 and 4 in the 9x9).
Spoon remaining salsa verde over the filled tortillas: 1/2 cup on the larger dish and 1/4 cup on the smaller dish.
Top the enchiladas with cheese: sprinkle 1 cup shredded Monterey Jack and 1/2 cup crumbled queso fresco over the large dish, and 1/2 cup shredded Monterey Jack and 1/4 cup crumbled queso fresco over the small dish.
Cover both dishes with foil and bake for about 25 minutes, until cheese is melted and enchiladas are heated through; optionally remove foil and broil briefly to brown the tops.
Garnish with cilantro, sliced jalapeno, sliced green onions, and serve with lime wedges.