In a large skillet, cook chorizo, onion, red pepper and jalapenos over medium heat until cooked through and vegetables are tender, 7-8 minutes, breaking chorizo into crumbles; drain. Cool slightly., In a greased 5-qt. slow cooker, layer a third of the potatoes, chorizo mixture and cheese. Repeat layers twice. In a large bowl, whisk eggs, milk and pepper until blended; pour over top., Cook, covered, on low 4-4-1/2 hours or until eggs are set and a thermometer reads 160°. Uncover and let stand 10 minutes before serving. If desired, top with chopped avocado and tomato.