In a large bowl, combine 2 cups of pre-cooked white cornmeal, 1 teaspoon of salt, and 1 tablespoon of vegetable oil. Gradually mix in 1 ¼ cups of warm water (100°F to 110°F) until the mixture is smooth and free of lumps. Let the dough rest for 5 minutes.

Divide the dough into six equal portions and roll each into a ball. Gently flatten the balls into discs approximately 4-5 inches wide and about ½ inch thick.

Heat a skillet over medium heat and brush with a thin layer of vegetable oil. Add the arepas to the skillet, cooking each for about 6-7 minutes per side until golden brown. Transfer to a preheated oven at 350°F (175°C) and bake for an additional 10-15 minutes for extra crispiness.

In a mixing bowl, combine shredded rotisserie chicken, finely chopped onion, cilantro, and jalapeño (if using). In another bowl, mash a ripe avocado with 2 tablespoons of mayonnaise and the juice of one lime. Mix both mixtures together, seasoning with salt and pepper to taste.

Once your Homemade Arepas are golden and crispy, carefully slice open one side to create a pocket. Fill each arepa with the creamy chicken and avocado mixture.