In a medium pot over medium heat, add oil and onions and cook two minutes. Add garlic and the ground beef and cook, breaking up the beef. Cook until no longer pink.

Add the canned tomatoes including the juice, salt, pepper, cumin, chili powder and oregano and on a medium simmer, cook ten minutes. Remove from heat.

In a larger pot, heat half and half over medium heat and once hot, slowly add the American and cheddar a little at a time, stirring as you go. Keep adding until all of the cheese has melted in. A non-stick pan is best for this.

Add in the drained green chilis and stir.

Place the 24 or more pickled jalapeno slices in a small food processor or blender and puree until smooth. (Add a few spoonfuls of the chili to the blender or food processor just to bring the volume up high enough for the blades to reach, if necessary.) Then pour the contents into the queso and stir.

Pour the chili into the queso, leaving out any excess liquid or fat that settled from the chili.

Stir and serve warm with tortilla chips.