1. Bake tater tots according to package directions.
2. Meanwhile, cook bacon over medium/medium-low heat until crisp. Transfer bacon to a paper-towel lined plate to drain. Remove all but 1 tablespoon of bacon grease from pan. Add red onion and cook over medium heat until softened and a translucent, about 4 minutes, stirring occasional. Add garlic and chili powder and cook for about 30 seconds, stirring frequently to avoid burning. Stir in beans and tomatoes and cook until heated through, about 3 minutes.
3. Transfer tater tots to serving dish and top with bean mixture, queso, bacon, scallions, cilantro, and a generous spoonful of sour cream. Devour immediately.

for the Queso

1. Melt butter in a medium skillet over medium/medium-low heat. Add flour and stir constantly for 1-2 minutes. You want to cook away the raw flour taste, but not let it get too brown.
2. Add whole milk and stir until the roux (butter-flour mixture) has been completely incorporated. Cook, stirring occasionally, until the milk has thickened slightly (it will probably beging bubbling a bit) and it coats the back of a spoon. Remove pan from heat, add cheeses and season with Kosher salt and freshly ground black pepper, and stir until fully melted.