Bring a large pan of water to the bowl and cook the peas for around four minutes. Remove from the pan with a slotted spoon and set aside.
At the same time add the pine nuts to a dry skillet over a medium heat and stir regularly until toasted then remove from the heat and set aside.
Add the pasta to the boiling water and cook according to the packet instructions.
When the pasta is almost done, pulse one cup of the cooked peas with a few tablespoons of the pasta water until just chopped. Add in the lemon zest and ricotta, parmesan, salt and pepper and pulse again.
Drain the pasta reserving a cup of the water before you do.
Tip the peas and ricotta mixture into the hot pasta with the reserved whole peas and stir to coat all the pasta. Squeeze over the fresh lemon and add a little of the reserved pasta water if required to loosen the sauce.
Serve in bowls, topped with the pine nuts and a little more parmesan.