Step 1Preheat oven to 180°C. Bring a small saucepan of water to the boil over high heat. Cook sweet potatoes for 6–8 minutes, or until tender when pierced with a skewer. Drain. Cut into wedges.
Step 2Heat oil in a medium cast-iron or ovenproof frying pan over medium heat. Cook corn and capsicum, stirring, for 5–7 minutes, or until the capsicum is almost tender. Add sweet potato, black beans and ground coriander. Cook, stirring, for 2–3 minutes.
Step 3Meanwhile, whisk the eggs and milk together in a large jug. Season well with cracked black pepper, to taste.
Step 4Pour the egg mixture into the bean mixture and cook for 2–3 minutes, or until frittata is beginning to set around the edges. Scatter with half of the coriander leaves. Place in oven. Bake frittata for 15 minutes, or until golden and just set.
Step 5Top the frittata with avocado, chilli and coriander leaves. Slice and serve with salad leaves.