Finely chop the onions. Crush or finely chop the garlic. Finely chop the parsley stems and coarsely chop the parsley leaves. Coarsely grate the zucchini. Thinly slice the chorizo.
Step 2 — Brown chorizo
Put the chorizo in a cold medium deep frypan over medium-high heat. Cook, turning, for 4-5 mins until golden. Bring a medium saucepan of salted water to the boil for the pasta.
Step 3 — Cook pasta sauce
Add the onion, garlic and parsley stems to the chorizo and cook, stirring occasionally, for 3 mins or until softened. Stir in half the tomato paste* and a pinch of chilli flakes* (see cooking tip) and cook, stirring, for 1 min. Add the tomatoes, zucchini and 60ml (¼ cup) water, reduce the heat to medium-low and cook for 15 mins to develop the flavour.
Step 4 — Cook pasta and peas
Meanwhile, cook the pasta in the pan of boiling water for 8 mins. Add the peas and return to the boil. Cook for 1 min or until the pasta is al dente. Reserve 2 tbs cooking water, then drain the pasta and peas.
Step 5 — Season sauce
Stir ½ tsp sugar into the pasta sauce. Taste, then season with salt and pepper.
Step 6 — Get ready to serve
Add the pasta, reserved cooking water and remaining parsley to the pasta sauce. Increase the heat to high and cook, stirring constantly, for 1 min or until well combined. Divide the pasta among bowls to serve.