On a sheet pan lay out red onions rings and coat with olive oil. Season with salt and grill onions until soft and tender. After chilling, dice small. In a medium mixing bowl mix together red onions, garlic, avocado, cilantro, jalapeno, corn kernels and black beans. (being careful not break up avocados). Season with lime juice and kosher salt. Chill and set aside. Drop tortillas into 350 degree frying oil. Press each tortilla down with 2-ounce ladle to form a cup. Do them one by one. Remove with slotted spoon. On a tray or 8 plates lay out tortilla cups. Then fill cups with avocado roast corn salad and garnish with queso cotija.