Cook the potato in a large saucepan of salted boiling water for 7-8 minutes or until tender. Drain.
Heat a 22cm-diameter (base measurement) non-stick frying pan over medium-high heat. Add the chorizo and cook, turning occasionally, for 3-4 minutes or until golden. Transfer to a plate.
Add potato to pan and cook, turning occasionally, for 3-4 minutes or until golden brown. Return the chorizo to pan along with the ham and spinach and cook, tossing, for 1-2 minutes or until spinach wilts.
Preheat grill on high. Whisk together the eggs and shallot in a small bowl. Season with salt and pepper. Pour the egg mixture into the pan. Reduce heat to low and tilt the pan slightly to evenly distribute the egg. Cook for 4-5 minutes or until the frittata is set around the edge but still runny in the centre. Place the pan under the grill and cook for 3-4 minutes or until golden brown and just set.
Combine rocket, chives and parmesan in a bowl. Cut frittata into wedges. Serve with rocket salad.