For this quick and easy frittata, sweet potatoes not only look like ochre jewels within the blanket of fluffy egg, but they add a lovely sweetness. It's a no-fuss midweek meal that's ready in just 20 minutes
Heat the oil in an ovenproof frying pan and add the onion and sweet potato. Cook over a medium/low heat for about 8-10 mins until softened and golden.
Beat the eggs in a bowl or jug, then mix in the cheese, salt and pepper.
Pour into the frying pan over the vegetables and arrange the asparagus on top.
Cook on the stovetop over a medium/low heat for about 5 minutes, or until the base and edges begins to set, but the centre is still liquid. Meanwhile, turn on the grill to heat it up.
Place the pan under a hot grill for a few more minutes until the top begins to puff up and is lightly browned.