Heat the olive oil a skillet over medium heat. Add the spicy ground sausage or ground chorizo sausage to the skillet, and cook it until browned and cooked through. Use a spatula or meat masher to break the meat up into small pieces as it cookies. Remove the cooked ground sausage from the skillet, drain the meat, and set it aside.
Next, add the sliced Anaheim chile peppers and onion to the skillet. Sauté the vegetables until they are softened and slightly caramelized, about 5 to 7 minutes. Remove the onion and pepper from the skillet, and set them aside.
Shred or cube the cheese and set it aside. In a saucepan, melt the butter over medium heat. Stir in the flour and cook for 1 to 2 minutes, or until the mixture is light golden brown, to make a roux.
Slowly pour in the milk or cream, whisking constantly to prevent lumps from forming. Cook the mixture until it thickens, about 2-3 minutes.
Reduce the heat to low and gradually add the cheese in batches, stirring continuously after each batch until the cheese is melted and smooth.
Stir in the cooked and drained spicy ground sausage, sautéed Anaheim chile peppers and onions, chili powder, and garlic powder. Cook the queso dip for a few more minutes, stirring occasionally, until it reaches your desired consistency or thickness.
Remove the queso from heat, and season it with salt and pepper to taste. Serve the queso dip warm with tortilla chips, sliced veggies, or your favorite dippers.