While you start prepping for the dip, set the oven for preheating at 400°F.
Lightly grease a baking pan.
Now put the Cream Cheese in a mixing bowl. Then stir in half-and-half until it is completely blended.
Take a large bowl, stir in Monterey Jack Cheese, Onion, Green Chiles, and Jalapeno. Mix them well.
Add chopped Spinach to the bowl and mix evenly.
Now spread the Spinach mixture in the baking pan and bake it for 20-25 minutes or until it becomes bubbly.