Wash the zucchini and grate them finely with a hand grater or food processor.
Chop the shallot.
Prepare the stock and keep it warm.
In a large frying pan with fairly high sides, fry the shallot in a little olive oil. As soon as it starts to brown, add the rice.
Fry for 2/3 minutes over medium heat, stirring regularly, until the grains become translucent.
Add the white wine all at once and continue to stir, lowering the heat a little.
When the rice has absorbed the wine, add one or two generous ladles of stock to cover the rice. Stir regularly.
Once the stock has been absorbed, add the grated zucchini, and cover again with stock. Continue to stir regularly.
Continue to add stock gradually as soon as there is more, stirring well to prevent the risotto from sticking to the pan. After about fifteen minutes, the risotto is cooked (taste it and adjust the cooking time. I like it a little al dente).
Turn off the heat and immediately add the sliced butter and cheese. Stir well from the bottom of the risotto upwards. Depending on the texture of the risotto and if you want to make it creamier, you can add a little more butter or stock.
Add salt and pepper, thyme and mix again.
It's ready! Enjoy your risotto straight away!