Preheat the oven's broiler and set the oven rack about 6 inches from the heat source.
Broil the corn until the kernels are slightly charred at the tips, about 5 minutes, turning often. Remove corn, cool, and cut the kernels from the cob; transfer kernels to a bowl.
Heat olive oil in a skillet over medium heat; cook and stir poblano peppers, jalapeno peppers, and red onion until peppers and onions are tender, about 8 minutes; mix in corn and butter. Cover skillet and simmer mixture for 10 more minutes to combine flavors.
