In a small saucepan, combine the cream, lemon zest and pepper, stirring to combine. Leave to infuse while you prepare the vegetables.
In a medium sized pot, combine the lemon juice for the vegetables with 2 or 3 cups of water. We’re blanching the vegtables in the lemony water to give them some brightness and a lemon hit, so don’t add too much water to pot or you’ll dilute the lemon. Blanch the beans first, followed by the broccoli and peas. I like to leave them for a couple of minutes so they’re a little cooked but still green and crunchy. You can cook them as long as you prefer, keeping in mind they won’t get cooked again.
As you blanch the vegetables, remove them from the water with a slotted spoon, and set aside in a bowl or sieve. You can refresh them in some cold water to stop the cooking, if you fancy. I don’t bother.
Once all the vegetables are blanched, fill the pot with enough water to cook the pasta. The lemon water should still be in the pot. Add a generous amount of salt, and allow the water to come to the boil before cooking your pasta as per packet instructions. Remember to save some pasta water from near the end of the pasta cooking process – we will use it to thin the sauce.
While the pasta is cooking, place the cream mixture on a low heat. Allow it to cook and infuse the lemon for a few minutes before adding the mustard. Keep it on a very low heat.
Once the pasta is cooked, drain it (again, remember that pasta water!) and place it into a large mixing bowl, or even back in the pot.
Turn the heat off on the cream mixture. Add the grated parmesan to the creamy sauce, big spoonfuls at a time. Stir the last spoonful before moving onto the next – this ensures the cheese melts into the sauce, and you don’t end up with any lumps of cheese.
Once all of the parmesan has been stirred into the sauce, adjust it for seasoning. You might not need to add extra salt, but keep in mind that this small quantity of sauce covers 6 large servings of pasta. I generally add 1 teaspoon of sea salt flakes.
Pour the sauce over the pasta, and use tongs to quickly distribute it evenly across the pasta. Use the remaining pasta water to thin the sauce out to your desired consistency. Use a splash at a time, because you can’t take it back once you’ve overdone it. I generally add about 1/2 – 1 cup, because the pasta does suck a lot of liquid up as it cools.
Top the pasta with the blanched green vegetables, herbs and toasted hazelnuts. Season with generous freshly cracked black pepper, and any other fresh veg you fancy (rocket, radicchio, spinach or some sort of salad green would all be lovely)