Pierce potatoes several times with a fork; place on a foil-lined baking sheet.
Bake at 425 for 1 hour or until tender. Cool slightly; peel and mash in a large bowl. Stir in milk and next 4 ingredients (through cheese).
Cook pasta according to package directions, omitting salt and fat; drain.
Add pasta to sweet potato mixture; set aside.
Preheat broiler to high.
Heat a large ovenproof skillet over medium heat.
Add oil; swirl to coat.
Add chorizo to pan; cook 4 minutes or until browned, stirring to crumble.
Place chorizo in a small bowl. Wipe pan clean. Spoon sweet potato mixture into pan; sprinkle evenly with chorizo. Broil 2 minutes or until lightly browned and crisp.