Place the poblano pepper under a broiler, turning occasionally until the skin is charred and blistered on all sides.
Transfer the pepper to a bowl and cover with a lid for 5 minutes to steam, then peel away the charred skin, remove the seeds, and roughly chop.
In a high-speed blender, combine the roasted poblano, Greek yogurt, lime juice, garlic powder, sea salt, and black pepper, blending until completely smooth.
In a medium mixing bowl, combine the shredded cooked chicken breast and sweet corn kernels with 2 tablespoons of the prepared poblano sauce.
Lightly toast the corn tortillas in a dry skillet for 30 seconds per side to make them pliable, then fill each with the chicken and corn mixture.
Roll the tortillas tightly and place them seam-side down in a small oven-safe baking dish.
Pour the remaining roasted poblano sauce over the enchiladas and top with the shredded Monterey Jack cheese.
Bake at 375°F for 15 minutes until the cheese is melted and golden and the sauce is bubbling.
Garnish with freshly chopped cilantro before serving warm.