Heat 2 tablespoons of olive oil in a large, heavy-bottomed pot and add jalapenos, tomato, onions, garlic salt and pepper. Saute until softened, about 7-8 minutes. If the vegetables get too dry, add a few tablespoons of water.
Add canned chicken with juices to the pot, breaking up the chicken into little pieces. Mix well and saute until almost dry, about 7-8 minutes. When done, set aside to cool.
While chicken mixture is cooking, put green salsa, yogurt, water and garlic into a blender and blend on high until liquified. Set aside.
Heat 1/2 cup oil over medium-high heat until it shimmers. Using tongs, slide in a tortilla until one side is coated with oil, then flip over and coat the other side. It should sizzle slightly and the tortilla may puff up a bit. Allow excess oil to drip from tortilla back into pan. Remove after a few seconds on each side to a paper towel-lined plate to cool. Repeat with remaining tortillas.
Divide cheese in half and set 2 cups aside to top enchiladas.
Using a spoon, divide chicken mixture into 10 small piles. Do the same with 2 cups of the cheese.
To assemble enchiladas, have a 9x13 inch baking pan ready. Take a tortilla and spread 1 pile of chicken mixture in a line down the center. Sprinkle with 1 pile of cheese. Roll tightly and place in one end of the baking pan seam side down. Repeat with remaining tortillas.
Pour green chile sauce over enchiladas, making sure they are all completely covered. Sprinkle evenly with remaining cheese and bake for 20 minutes.
If you like a browned top, broil for a few minutes, keeping a close eye on them so as not to burn. Top with green onions and serve.