In a medium bowl, combine the peeled and pitted Haas avocados with mayonnaise and lime juice. Use a fork to mash until creamy, then fold in the shredded chicken, red bell pepper, onion, cilantro, jalapeño, and garlic. Season with salt and pepper, cover, and refrigerate for later.

Set your oven to 350ºF and arrange an oven rack in the center.

In a large bowl, stir warm water with salt until dissolved. Gradually add the precooked white corn flour, mixing with your hands until smooth; knead out any lumps. Let the dough rest for 3-5 minutes.

Divide the dough into 8 pieces, rolling each into a ball. Flatten the balls into discs about 3½ to 4 inches wide and ⅓ to ½ inch thick. Set the formed discs on a platter.

Lightly oil a large non-stick skillet and heat over medium. Working in batches, cook the arepas for about 4 minutes on each side until they develop some color and golden spots.

Transfer the fried arepas directly onto the wire oven rack and bake for 15-20 minutes until puffed and with a taut skin. Allow them to cool slightly before handling.

Carefully slice each arepa horizontally and stuff with the creamy avocado chicken salad. Serve warm.