Step 1Preheat the oven to 200°C. Place the leftover vegetables, chopped spinach, cheddar, shallots and garlic in big bowl. Add lemon zest and mix well.
Step 2Heat 1 tablespoon olive oil in a large, deep, non-stick and ovenproof frying pan over medium-high heat. Add vegie mixture. Cook, stirring gently, for about 2 minutes.
Step 3While vegetables are heating, whisk eggs in another bowl. Pour eggs over vegetables in hot frying pan, then reduce heat to low and cook for a further 1–2 minutes.
Step 4Sprinkle over parmesan and place pan in hot oven for about 10–12 minutes, or until frittata is golden and cheese is bubbling. Remove from oven, season with cracked black pepper, scatter over basil and cut into quarters. Dress salad leaves with lemon juice. Serve frittata with salad.