Step 1

Heat the oven to 200C/fan 180C/gas Drop the asparagus in boiling salted water, bring back to a simmer then cook for 2 minutes. Tip in the peas then drain everything through a colander.

Step 2

Heat the olive oil in a frying pan and add the leeks with a good pinch of salt. Cook for 8-10 minutes or until really soft. Add the garlic and cook for 2 minutes. Add the spinach and cook until just wilted.

Step 3

Reserve 4 tbsp of the ricotta and stir the rest into the leeks and spinach, along with the asparagus, peas and artichokes. Mix well then add enough vegetable stock (about 250ml) to make it a little saucy but not watery. Take off the heat and stir in the pesto.

Step 4

Put a 1/4 of the sauce in the bottom of a 30cm x 22cm baking dish. Pour boiling water into a separate baking dish then carefully dip each lasagne sheet in before covering with the sauce (this will help the lasagne stay saucy). Repeat 3 times, finishing with a layer of lasagne sheets.

Step 5

Mix the rest of the ricotta with another splash of vegetable stock and spread over the top layer. Scatter over the grated cheese and bake for 20-30 minutes or until golden and bubbling.