First, roast your poblano pepper. Turn your oven to broil and let it heat for a few minutes. While it's heating, line a baking sheet with aluminum foil. Using your hands, coat the poblano pepper with high heat oil and place on the sheet.
Broil the pepper in the oven for 5-7 minutes on each side, making sure it doesn't burn. Once both sides are nice and brown, remove the pepper from the oven and set aside in a bowl, covering it with foil. Let it sit covered for about 15 minutes, allowing it to sweat.
While the pepper is roasting, chop/prep your remaining ingredients. Combine the chopped red onion, jalapeño pepper (core and seeds removed), and fresh cilantro. Place into a large bowl and set aside.
After the pepper has cooled, put on food prep gloves and use your hands to peel the outer layer of skin off. Then cut the top off, and peel the flesh away from the core and seeds. Then just chop up that pepper to be ready to add to your salsa.
Squeeze lemon and lime juice into a bowl, removing any seeds.Pour the citrus juices into the bowl along with a large pinch of sea salt and stir until well combined. Taste and add more salt if needed.
Serve immediately. You can store any leftovers tightly covered in the refrigerator for up 4 days.