In a medium sauce pan, heat the olive oil over medium heat. Add the chopped red onion and Sauté until softened and beginning to brown, about 5 minutes.

Remove half of the cooked onion and set aside. 

Add in the chili powder, smoked paprika, cumin, oregano, salt and pepper. Stir to combine. Stir in the tomato paste, tomato sauce and the water. 

Bring the sauce to a boil stirring constantly. Reduce the boiling sauce to a simmer; cover, and cook for 30 minutes, stirring occasionally, the sauce will be thick.

Let the sauce cool for 10-15 minutes for easier handling.

While the sauce is cooling, reserve a small handful of the chopped olives and green onions for the topping. Reserve about 1 cup of the grated pepper jack cheese also, separately. 

In a large bowl combine the remaining sliced olives, sliced green onions, shredded pepper jack cheese. Stir in the cubed chicken reserved cooked red onion, and the sour cream or Greek yogurt. 

Preheat oven to 350. 

Spray a 9 by 13 inch casserole dish with cooking spray or olive oil. Have a pie plate or large dinner plate ready to help assemble the enchiladas. 

Onto the bottom of the prepared casserole dish spread 2 cups of the thick sauce. Covering the entire bottom.

Spread about 1 1/2 cups of the cooled sauce onto the pie plate covering the bottom.

Place a tortilla over the sauce and press down to coat one side. Flip the tortilla over to coat the other side.

Place about 1/6 of the filling in a log down the center of the tortilla. Roll up and place in the prepared casserole dish. Repeat with the remaining tortillas. Using more sauce on the pie plate as needed.

Pour over the finished enchiladas the remaining sauce. Making sure to cover each tortilla completely. Sprinkle the reserved Grated pepper jack cheese and then top with the reserved sliced olives and sliced green onions. 

Bake uncovered for 30 to 40 minutes, until the cheese has melted and started to brown. 

Serve with more sour cream or avocado slices.