Start by shucking and boiling the corn for about 3-5 minutes. Once cooked, allow it to cool before cutting the kernels off the cob. If you're using canned corn, simply drain the corn and set it aside.
In a large mixing bowl, combine the corn, diced red onion, chopped cilantro, and diced jalapeño peppers.
In a separate bowl, whisk together the fresh lime juice, olive oil, salt, black pepper, and adobo sauce. The adobo sauce adds a smoky flavor to the salsa, so don't skip it if possible.
Pour the dressing over the corn mixture and toss everything together until well combined. Taste and adjust the seasoning as necessary.
Cover the bowl with plastic wrap and refrigerate for at least an hour to let the flavors meld together. Before serving, give the salsa a good stir and sprinkle some extra cilantro on top if you like.