Set instant pot to saute and add 1 tablespoon oil. Saute onions, garlic and jalapeno until onions start to soften, about 3 min. Add chicken broth, tomato sauce, chili powder, sugar, cumin, salt and pepper to pot and stir to combine. Add chicken breasts to instant pot, close lid and set pressure release valve to sealing. Set instant pot to high pressure via manual mode for 10 minutes. The instant pot will take about 10 min to come to pressure, then will countdown from 10 minutes. While chicken breasts and sauce are cooking, shred cheese and combine and prepare tortillas. To prepare tortillas preheat oven to 400°. Brush tortillas with vegetable oil, spread on a baking sheet and heat in over for 5 minutes, just until soft and pliable. Once instant pot has completed 10 min countdown, it will beep and switch to the keep warm function. Carefully turn pressure release valve to venting to quick release pressure. Remove chicken breasts and set aside to cool, then shred. Stir 2 tablespoons of chopped fresh cilantro into the enchilada sauce. Spray a 9×13 baking dish with non stick cooking spray. Use 1/4 cup of enchilada sauce from the instant pot to spread on bottom of baking dish. To assemble enchiladas, evenly divide 1/2 enchilada sauce, 1/2 shredded cheese and all of the shredded chicken among the 12 tortillas, roll and place seam down while in baking dish. Pour remaining enchilada sauce over rolled enchiladas and top with remaining cheese. Cover dish with foil and back at 400° for 20-30 min or until heated through. Sprinkle with additional fresh cilantro and serve with sour cream.