Finely dice the red onions and mince the jalapeño, removing seeds if you prefer less heat. Dice the green bell pepper into small, uniform pieces about the same size as the corn kernels so everything has a consistent texture. If using fresh corn on the cob, cut the kernels off with a sharp knife; if using pre-shucked corn, simply measure out 2 cups. Roughly chop the fresh cilantro and set aside.

In a medium bowl, combine the prepared corn, diced onions, bell pepper, and minced jalapeño. I like to squeeze the lime juice directly over the vegetables at this point because the acid begins to slightly soften the onions and mellow the jalapeño's heat while everything sits. Add the kosher salt, black pepper, and ground cumin, then drizzle with extra virgin olive oil.

Gently fold all ingredients together until evenly mixed, then fold in the fresh cilantro—I add it just before chilling rather than earlier because it stays brighter and more fragrant when mixed in at the last moment. Cover the bowl and refrigerate for at least 1 hour to allow the flavors to meld together. The salsa tastes even better after a few hours or even overnight, as the lime juice continues to season everything.