In a medium-hot pan, cook the onion and garlic until the onion starts to soften, about 4 minutes. Do not brown.
Add the chiles and cook for another 4 minutes.
Add the corn and cook for 2 minutes.
Turn off the heat and add the cream. Stir to incorporate.
Add the cheese and stir continually until the cheese is just melted.
Check the salt and add salt if needed.
Serve immediately on hot tortillas.
You can substitute sour cream for Mexican cream (crema Mexicana). You can substitute mozzarella or Monterey Jack or any mild white cheese that melts well. You can serve on flour tortillas if you'd like.
It will keep in the refrigerator for up to 3 days although it is best eaten when freshly prepared.
Reheat in the microwave until it is just heated through, 1 to 2 minutes.