Preheat your oven to Combi Steam, 350°F/180°C, 70% (high) humidity. Have a large oven-safe skillet or baking dish ready to make the pasta sauce.
Quarter each zucchini lengthwise, then slice into roughly 3/4 inch (2cm) chunks. Squash the garlic cloves to bruise, and peel off the skin (no need to chop them). Put the zucchini and garlic into your baking dish.
1.5 lb zucchini, 3 cloves garlic
Sprinkle the salt and pepper over the vegetables in the dish, then drizzle with the olive oil. Add half a cup of water to the pan, and put it into the oven. Cook until the zucchini is browning on top and soft enough to easily squash with a fork, about 25 minutes.
1.5 tsp flaky salt, 1 tsp ground black pepper, 1/2 cup extra virgin olive oil
While the zucchini is cooking, heat a large pot of water, salt well when it comes to the boil, and cook the pasta according to the package directions. Drain, saving about a cup of the starchy pasta water, then cover and set aside if it's ready before the sauce is finished.
1 lb dried pasta
When the zucchini is done, remove it from the oven and use the back of a fork or a potato masher (much quicker and easier than a fork!) to break it up and make a chunky sauce. Make sure you mash the garlic cloves well so there aren't big pieces of garlic through the sauce. Give it a good stir to bring together the vegetables and any liquid or olive oil that haven't been incorporated.
Add the zucchini to the hot cooked pasta, with most of the parmesan cheese and about half of the pasta cooking water. I like to hold a little cheese back just to make sure my seasoning is right. Toss the pasta and sauce together to combine well, and check seasoning and viscosity of the sauce. If needed, add the remaining cheese or some additional pasta water to loosen things up. When you're happy with it, serve immediately with extra cheese and torn basil leaves.
3/4 cup finely grated parmesan cheese, 3 sprigs fresh basil