Heat olive oil in a large soup pot over medium-high heat. Add onions garlic and jalapeno peppers. Saute until softened, about 5 minutes.
Tear corn tortillas into small pieces and add to the pot with the vegetables.
Salt and pepper to taste. Simmer, uncovered, stirring occasionally, for 30 minutes. Strain the broth through a sieve, pressing hard against the vegetables with the back of a spoon to extract all the juices and flavor. Heat broth, if needed, before serving. Top with a small mound of tortilla chips and serve at once.