Over medium heat, season a large sauce pan with oil.
Add the onion and peppers and season with 1 tsp garlic powder and a pinch of salt. If adding any spicy peppers, add them with the bell peppers and onions. Sauté until tender, about 5-7 minutes.
Add the milk, cream cheese and cheese and mix together until creamy. Whisk to make sure there are no chunks from the cream cheese. If the mixture is too thick for your taste, add more milk or you can even diffuse with water. Only add a little bit at a time and mix if you are doing this.
Once the queso is creamy and your desired consistency, pour the mixture into an oven safe skillet. Sprinkle a handful of cheese on top and spread it out evenly. Broil on the second highest rack until the cheese is melty and golden brown (every broiler is different, but my electric broiler took 3 minutes. If you have a gas broiler, this will take probably 1 minute.)
Top with scallions, cilantro, chopped tomatoes and chopped red onion. Or top with whatever you want :)
If you have enough self control and somehow have leftovers, seal them in an air-tight container for 3-4 days in the fridge. ENJOY!