Heat the olive oil in a pan over medium heat. Add 300g zucchini and stir for 5 minutes until soft and all the excess liquid has evaporated. Transfer to a bowl and cool.
Add the ricotta, half the parmesan, flour and egg to the zucchini mixture, season with salt and pepper, then stir to combine.
Line a large oven tray with cooking paper.
Bring a large saucepan of salted water to the boil, then reduce heat to a rolling simmer. Using 2 small tablespoons, scoop quenelles of the mixture into the water. Working quickly, repeat to make about 10 gnocchi.
Cook for about 3 minutes, the gnocchi will float to the surface. At this point, test the first one to see how much longer they need (it will depend on the size you have made them). Remove with a slotted spoon and place on tray.
Repeat until all the gnocchi are cooked, cool, cover and refrigerate until needed (up to 3 days).
To make the zucchini and radish ribbons, cut the 3 zucchini length ways into thin ribbons and slice the radishes very thinly and toss with the extra virgin olive oil, lemon juice and season with salt and pepper.
To serve, heat grill to medium/high. Scatter gnocchi with remaining 40g parmesan, then grill for about 8 minutes or until gnocchi are golden and warmed through.
Divide gnocchi between bowls and top with zucchini and radish ribbons and scatter with chervil or basil and extra parmesan. Drizzle with oil to serve.