HEAT oven to 350°F.
HEAT 2 Tbsp. oil in 10-inch ovenproof skillet on medium-high heat. Add potatoes; cook 5 to 7 min. or until tender, stirring frequently. Remove from skillet.
COOK and stir onions in remaining oil in same skillet 3 min. or until crisp-tender. Add chorizo and ham; cook 2 min., stirring frequently. Stir in peas; cook and stir 3 min. Remove skillet from heat.
ADD potatoes; mix lightly. Pour eggs over potato mixture.
BAKE 25 to 30 min. or until center is set. Top with Singles pieces; let stand 5 min.