Fresh lasagne with pesto

Name: Fresh lasagne with pesto
Ingredients: 1.2l milk; 100g butter cut into pieces; 100g plain flour; pinch of freshly grated nutmeg; 500g baby spinach leaves; 250g lasagne sheets – fresh is best; 3 rounded tbsp good quality pesto; 500g cherry tomato on the vine, two or three vines left whole; good handful of basil leaves (or one supermarket pack); 175g piece fresh parmesan (or vegetarian alternative), coarsely grated; 2 x 150g balls mozzarella preferably buffalo, torn into bite-sized pieces