Preheat the oven to 350℉
Heat oil in a cast iron pan. Add the onions and garlic, sauté for 2 minutes. Add the serrano peppers and bell peppers and sauté for a minute or two with 1/8 tsp salt. Keep aside in a bowl. Add the corn to the bowl.
Add the rest of the ingredients reserving half cup shredded cheese. Mix to combine all the ingredients well.
Transfer to a baking dish. Top with the reserved cheese.
Bake for 16-18 minutes till it is bubbly. Broil for a minute or two for a little golden brown color on top.
Sprinkle with extra cilantro and/or some jalapenos. Serve warm with tortilla chips