How to Make It
Preheat oven to roast at 450°. Line a baking pan with parchment paper.
On the lined baking pan, toss together the corn, scallions and oil. Season with salt and pepper, and then spread into an even layer. Roast for 10-15 minutes, or until the corn is lightly browned and scallions are soft.
In a bowl, mash the avocado with a fork until it is nearly at your desired consistency. Stir in the corn, green onions and lime juice. Season with salt and pepper to taste.
Gently fold in the tomatoes. Serve immediately or else press a piece of plastic wrap flush into the top of the guacamole, refrigerate and serve preferably within 24 hours.