1. To make the pasta: Place the flour, three whole eggs and one egg yolk in a food processor (or large mixing bowl), and blend until you are left with a crumbling, slightly wet dough (add a drop of water if needed to bind). Cover with cling film and keep for at least 30 minutes in the fridge.
2. For the onion sauce, sweat the onions and butter in a pan on a medium heat for 30 minutes. Add the cream, lemon juice, salt and pepper, and cook out for a further 15 minutes. Blend together and pass through a sieve.
3. Set the rollers of your pasta machine to the wide setting. Take a third of the dough and roughly flatten between your hands. Roll the pasta through the rollers twice on each setting, until you get to the finest one.
4. When the pasta is rolled, lay it out on a clean counter top, dusted with semolina. Dust a light layer of plain flour on top.
5. Prepare the filling by placing the ricotta, spinach, lemon zest and grated cheese in a food processor (or in a bowl, using a whisk), and blitz until smooth. Season with salt and pepper.
6. Place a spoonful of the ricotta mix on the rolled out pasta, and then add one egg yolk into the centre and rub a little egg white around the edge of the pasta. Place another layer of pasta on top, and gently press the pasta edges together, and use a cutter to cut out the ravioli. Sit the finished ravioli on semolina.
7. Bring a pot of water to a simmer, add some salt and then add the raviolis. Cook for four minutes. In a separate pan, heat the onion sauce and then add the raviolis into the onion sauce once cooked. Transfer to a serving dish and garnish with the chopped hazelnuts, olive oil and some salad leaves.

Find more of Gráinne O’Keefe’s spring recipes here.