"This creamy dip is excellent warm with fresh vegetables or with freshly made flour tortilla chips (I cut tortillas into triangles and bake or fry them with vegetable oil). If you have a taste for something a bit spicier, add some finely minced jalapeno, serrano or habanero chiles. Delicious!"
Combine pepper Jack cheese and milk in top of a double boiler over simmering water. Stir frequently, scraping down the sides with a rubber spatula to avoid scorching, until cheese is melted and well combined with the milk, about 5 minutes.
Stir onions, tomatoes, spinach, and red bell pepper into the cheese mixture. Cover and simmer until dip has thickened and flavors are well blended, about 15 minutes.