Preheat oven to 350 degrees F. Grease a 9×13 casserole dish with nonstick spray. Heat the spinach in the microwave oven on high for 5 minutes and squeeze dry. Drain the artichoke hearts and coarsely chop in a food processor. Combine all the ingredients except the jack cheese in a large bowl. Stir well. Transfer into the prepared casserole dish and sprinkle with jack cheese on top. Bake for 30 minutes. Top with a dollop of sour cream and serve with chips!