1. Preheat the oven to 200˚C/180˚C fan/gas mark 6.
2. Bring a large pot of salted water to the boil. Add the potatoes and cook for 4-5 minutes until just fork tender. Drain thoroughly and pat dry with kitchen paper. Set aside to cool.
3. Heat one tablespoon of oil in an ovenproof frying pan and cook the onion for 4-5 minutes until softened. Add the peppers and cook for 3-4 minutes. Season with salt and black pepper, then transfer to a plate and set aside.
4. In the same pan, heat two tablespoons of olive oil. Brown the potatoes on all sides, working in batches if necessary. Season generously with salt and black pepper. Add the ham, return the onion and peppers to the pan and toss everything together.
5. In a mixing bowl, whisk together the eggs, cream and some salt and pepper. Fold through the grated Cheddar. Pour the egg mixture into the pan over the ham and vegetable filling.
6. Cook over a medium-low heat for 4-5 minutes, using a rubber spatula to lift the cooked edges and allow the uncooked eggs to flow underneath until the outsides of the frittata are just set but the centre is still wobbly. Transfer to the oven and cook for 8-10 minutes or until the frittata is set.
7. Remove from the heat and allow to rest for 4-5 minutes, then transfer to a chopping board and cut into wedges. Serve warm or at room temperature with some tomato salsa for dipping.