Dice the onion and zucchini, set aside.
Split the broccoli in half. Roughly chop 1 half and cut the remaining half into small florets, set aside.
Place a medium shallow frying pan over a medium/high heat and add 3 tbsp of olive oil, the onion, zucchini, roughly chopped broccoli, garlic and a good pinch of salt.
Cook for 2 minutes, stirring often then add the silverbeet, stir through, cover the pan with a lid and cook for 2 more minutes to soften the veggies.
Blend the veggies with the Oat milk on a high speed to make a smooth, creamy sauce. Adjust the seasoning to taste.
Meanwhile Bring a large pot of lightly salted water to the boil and add the pasta, cooking for 9 minutes. Add the remaining broccoli floret to the pasta for the last 2 minutes of cooking then drain the the pasta, reserving a little pasta cooking water.
Stir the Green Goddess sauce through the pasta and broccoli florets, with the zest of 1 lemon, the remaining olive oil and adjust the seasoning to taste. Use a little pasta water to thin the sauce if required.
Serve the pasta scattered with basil leaves, a little extra drizzle of olive oil if desired and cut the lemon into wedges to squeeze over.