10 ounces processed block cheese, diced, such as Velveeta (see Cook's Note)
4 ounces Monterey jack cheese, coarsely shredded
2 ounces sharp Cheddar, coarsely shredded
One 10-ounce can diced tomatoes and green chiles, such as RoTel Original (see Cook's Note)
Tortilla chips, for serving
You can make this dip in a medium saucepan or 10-inch cast-iron skillet, but cast-iron holds heat better and will keep your queso warmer longer. To reheat, place the queso back on the stove and turn the heat to low. Stir until melted and smooth, about 2 minutes.