In a skillet, sauté some chopped onion and cook the zucchini, cut into small pieces, for a few minutes. Season with salt, pepper, and herbs to taste.

Blend the cooked zucchini in a food processor and let the mixture cool.

Mix the zucchini mixture with the egg yolk, breadcrumbs, and Parmesan cheese. Then add flour until the dough is firm enough to shape into quenelles using two spoons.

When the water boils, add salt and form quenelles from the dough, dropping them directly into the boiling water.

Sauté the gnocchi in a skillet with butter, pepper, sage, and a little cooking water as they float to the surface (this will take about 2-3 minutes).