Preheat the oven to 375°F (190°C). Put the spinach in a large pot, with just the rinsing water clinging to the leaves. Cover and wilt it over a low heat for about 5 minutes, turning it occasionally. Tip the spinach into a colander and allow to drain, but do not squeeze dry. Reserve 2 tablespoons of the juices.
Put the goat's cheese and ricotta in a large bowl and mix together, then take out half the mixture and set aside. Add the pesto and reserved spinach juice to the cheese in the bowl and blend until smooth. Stir in the spinach and nutmeg and seasoning to taste.
Lay the lasagna sheets in a roasting pan and pour over enough boiling water to cover. Leave for 5 minutes until softened, then carefully drain.
Spread one-third of the spinach mixture over the base of a 25 x 18 x 8 cm ovenproof dish. Scatter one-third of the tomatoes in an even layer over the spinach mixture, then cover with a layer of pasta, trimming to fit the dish. Add half of the remaining spinach mixture in a thin layer, top with half the remaining tomatoes and cover with pasta as before. Cover with the last of the filling and arrange the remaining pasta sheets over the top.
Whisk the reserved cheese mixture with the eggs, milk and seasoning. Pour over the lasagna, then sprinkle with a mixture of the breadcrumbs and Parmesan. Bake for 25 minutes until the topping is lightly set and browned. Serve while hot.
Each serving: 27.5 g protein, 21 g fat of which 11 g saturates, 31 g carbohydrate, 11 g fibre, 442 Calories