Zucchini, sweet potato & feta frittata

Ingredients (4 servings): ±700g sweet potato, peeled and cut into 2-3cm cubes 3 tablespoons olive oil 2 tablespoons balsamic vinegar 2 medium zucchini, ends trimmed, coarsely grated 125g feta, crumbled ¼ cup basil leaves, shredded ± 80g salad mix 6 tomatoes, quartered lengthways 1 onion, chopped 6 eggs, lightly beaten   Method: Preheat oven to…