Preheat oven to 425.
In a small bowl stir together the salt, pepper, onion powder, garlic powder, smoked paprika, and chili powder.
Add the potatoes to a small bowl, sprinkle with spices, toss to coat.
Add the oil to a baking sheet.
Add the potatoes to the baking sheet in one even layer, with one of the cut sides down.
Bake for 12 minutes. Turn the potatoes over so the other cut side is down.
Bake for an additional 12 minutes or until the potatoes are golden brown and fork tender.
While the potatoes are baking, make the cheese sauce.
Add the cornstarch, beer, cheese, cream, and chipotle to a blender or food processor. Process until smooth.
In a pot over medium high heat, melt the butter. Add the cheese sauce, cook until thickened and warmed.
Plate the potatoes, drizzle with cheese sauce. Sprinkle with cilantro and green onions.