Preheat your oven to 350°F (175°C). This will ensure your dip is bubbling and warm when it’s time to serve.
In a large mixing bowl, combine the drained black beans, white beans, and white shoepeg corn. Add the salsa verde and 1.5 cups of shredded Colby Jack cheese, along with the chopped Roma tomatoes and garlic salt. Stir until well combined.
Pour the mixture into your prepared baking dish, spreading it evenly. Top with the remaining Colby Jack cheese.
Place the baking dish in the preheated oven and bake for 25-30 minutes, or until the cheese is melted and bubbly.
Once out of the oven, let it cool slightly before garnishing with diced avocado. Serve warm with tortilla chips, pita, or fresh veggies.