Prep time: 5 mins   /  Cook time:45 mins


  • 1 kg / 2 lb zucchini
  • 1 brown onion , finely diced (1 cup)
  • 2 garlic cloves , minced
  • 3 tbsp olive oil , separated
  • 2 1/2 cups warm liquid: zucchini juices plus milk , heated in a pan (see directions)
  • 2/3 cups parmesan cheese , grated
  • 1/2 cup medium grain white rice (Note 6)
  • 2 tbsp flour
  • 2 tsp salt
  • Black pepper


Prepare the Zucchini

  1. Grate the zucchini and place in a large bowl. Sprinkle with 2 tsp salt and use your hands to mix through well.
  2. Place zucchini in a colander over a bowl to collect the juices that sweat out. Leave for at least 20 minutes.
  3. Squeeze the liquid out of the zucchini, straining the liquid through the colander to add to the zucchini juices collected.
  4. Rinse the zucchini under cold water for 15 seconds, then squeeze out excess water, but this time do not save the water that is squeezed out.
  5. Pat the zucchini with paper towels to mostly dry.

To Prepare Gratin

  1. Top up the zucchini juices with milk to make a total of 2 1/2 cups of liquid. Warm liquid in microwave or on the stove.
  2. Heat 2 tbsp olive oil in a large heavy base pan over medium heat. Add garlic and onion and sauté for 8 minutes until translucent and starting to turn golden.
  3. Turn heat up to medium high, add the zucchini and cook for 5 minutes, stirring frequently.
  4. Add flour and cook for 2 minutes, stirring constantly.
  5. Remove from heat. Add all but 2 tbsp of the parmesan cheese and stir quickly to combine.
  6. Do a taste test to check for seasoning. Add more salt if desired, and a good grind of black pepper. I do not add more salt as I don’t think it is required.
  7. Add rice and liquid. If making ahead, stop here, then proceed with the next step on the day of serving.

To Bake

  1. Preheat oven to 220C/425F
  2. Return pan to heat and bring to simmer.
  3. If the pan you are using is not ovenproof, pour the contents into a buttered baking dish.
  4. Sprinkle over the remaining 2 tbsp of parmesan cheese and drizzle over the remaining 1 tbsp of olive oil.
  5. Cover with lid or foil, then place in the top 1/3 of the oven.
  6. Bake for 15 minutes, then remove the lid/foil and bake for a further 10 to 15 minutes until the top is golden and the liquid appears to have been absorbed. (Tilt the dish slightly. If liquid pools then return to the oven for 5 minutes at a time.)
  7. Rest for 10 minutes. While resting, any residual liquid will be absorbed.
  8. Best served immediately.

Recipe Notes

1. The alternative to sprinkling salt over the grated zucchini and letting it sweat the juices out is to sauté them in batches in the pan. This is a faster method, but you won’t get the same flavour in this dish as the zucchini juices are used as the stock for this dish.

2. Cooking the onions slowly makes them sweet and caramelised. You can’t achieve the same result by sautéing them over high heat for a few minutes. But if you are in a rush, by all means turn up the heat and cook the onions faster.

3. When heating the zucchini juice/milk liquid, be careful not to over boil which might split the milk. Just warm it up.

4. The pan and baking dish need to be about 6 to 8 cup capacity. The oven proof pan I used is a 7 cup capacity pan.

5. To VEGANISE: Omit the parmesan cheese, do a taste test to make sure it is seasoned enough still (as the parmesan adds salt). Sprinkle the top with panko or breadcrumbs and drizzle with olive oil so you get a “crust” on the top similar to melted parmesan (well, actually, it will be even better!!) And substitute the milk with soy (or almond milk, but I prefer soy milk because almond milk has a slightly nutty flavour).

6. The medium grain white rice can be substituted with long or short grain white rice. This recipe is not suitable for: brown rice, arborio (risotto) rice, paella, basmati or jasmine rice.

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