Pre-heat broiler. In a large bowl, combine black beans, corn, ½ can green chiles, 4 oz shredded cheese, ancho seasoning, and fresh cilantro.
Halve the avocados, removing pit and hollowing out insides. Mash insides in a small bowl and set aside.
In a medium bowl, combine dressing ingredients plus the remaining green chiles. Stir to combine and fold in mashed avocados. Salt & pepper to taste.
Place avocado boats face up and fill each with 1/3 cup of filling. Sprinkle with cheese, then broil until cheese is melted, ~2 mins.
Remove avocado boats from oven and transfer to serving dish. Drizzle with dressing and garnish with more cilantro.