Preheat the oven to 350 and grease a 9x13 inch baking pan
Melt butter in a large skillet over medium heat, add in diced onion and a pinch of salt. Cook onions on medium for about 15 minutes or until translucent and slightly browned around the edges.
Add in drained green chilies and stir for a few minutes until heated through.
Place softened cream cheese in a large bowl, add in onions and chilies and stir. Mix chicken into the cream cheese mixture.
Stir until everything is evenly coated.
Spoon 1/8 of the mixture down the center of a tortilla and wrap it tightly.
Place seam side down in your prepared baking dish.
Repeat with remaining tortillas placing them side by side in the baking dish.
Sprinkle shredded cheese evenly across the top of the enchiladas.
Pour the heavy cream evenly across the top of the cheese.
Place in the oven and bake for 45 minutes or until golden brown and cheese is warm and bubbly.