Put the potatoes in a pan of cold water and bring to the boil. Cook for 5 minutes until tender. Drain and transfer to a large bowl. Add the spinach to the bowl and set aside, covered, for 5 minutes or until the spinach has wilted.
Meanwhile, finely chop half the bacon. Put the oil in a non-stick, ovenproof frying pan and set over a medium heat. Add the onion and chopped bacon and cook, stirring, for 6-8 minutes until the onion has softened. Transfer to the bowl with the potato mixture. Add the eggs and mix well.
Thinly slice the remaining bacon. Set the frying pan over a medium-high heat, add the sliced bacon and cook, stirring, for 5 minutes or until browned. Transfer to a small bowl.
Put the potato mixture into the pan and spread it out evenly. Cook for 8-10 minutes or until the base is golden and set. Heat the grill to high, then grill the tortilla for 5 minutes or until the top is golden and set.
Meanwhile, cook the peas in a pan of boiling water for 2 minutes until tender, then drain, refresh under cold water and drain again. Combine the peas, sliced bacon and cottage cheese in a bowl. Top the tortilla with the cottage cheese mixture, then serve with the salad leaves.