In a small skillet over medium heat, cook the pancetta until browned. Remove to a paper towel-lined plate. Set aside.
Meanwhile, remove the husk and silk from the corn. Using a grill pan or outdoor grill, grill the corn, the poblano, and the red pepper slice until tender and charred. Let cool for 5 minutes.
Slice the corn kernels off of the cob. TIP: lay the corn cobs on their side and cut the kernels lengthwise off of one side Then rotate the cob onto the flat side, cutting off the kernels from the next side. Continue rotating until all the kernels have been cut off. The corn cob is more stable laying on its' side and the kernels don't end up all over the kitchen.Add the corn to a serving platter or bowl.
Cut the grilled poblano in half lengthwise and remove the stem and the seed. Slice and chop half of the poblano and add to the corn. Save the remaining half for another use.
Chop the red pepper and add to the corn and poblano. Top with the pancetta, the feta or cotija cheese, and the scallions. Squeeze the lime juice over the top.
Serve warm, at room temperature, or cold. Refrigerate leftovers.