Place watercress, basil, garlic clove, lemon juice, blanched almonds, mint leaves, salt and 3 Tbsp of extra virgin olive oil in a blender. Whizz until smooth. Transfer to a bowl when done. Add nutritional yeast and more olive oil (I usually add 3 to 4 Tbsp) until you have your desired consistency. Set aside.
TO MAKE THE VEGETABLES & PASTA:
Remove and dispose of hard stalks of asparagus. Cut each asparagus in 3. Cut tenderstem broccoli in halves.
Heat two large pans of water.
When boiling, put the spaghetti into one of them.
When the spaghetti have only 10 mins left to cook, add asparagus to the other pan of boiling water. 2 minutes later add mangetout and broad beans. 1 minute later add the tenderstem broccoli. 2 minutes later the peas. Cook for another couple of minutes until vegetables are done. They should still have a bite.
By that time the pasta should be cooked. Drain pasta and vegetables. Transfer pasta to a large serving dish. Toss in pesto and vegetables.
Serve straight away topped with sliced spring onions, pine nuts and pink peppercorns.