Gather your equipment: a sharp knife, a large skillet, a wooden spoon, and a vegetable peeler.
Finely dice the onion and minces the garlic, filling your kitchen with a warm, savory aroma.
Heat olive oil in your skillet over medium heat, then add the diced onion and minced garlic, sautéing until they turn translucent and fragrant, about 5 minutes.
While the aromatics cook, use the vegetable peeler to grate the zucchini into fine strips or small shreds.
Add the grated zucchini to the skillet with the aromatics, cooking until it releases moisture and begins to brown slightly, about 8 minutes.
Pour in the crushed tomatoes, stirring to combine. Season with salt, pepper, and a pinch of red pepper flakes for a gentle heat, then bring to a simmer.
Reduce the heat and let the sauce simmer gently for about 15 minutes, stirring occasionally until it thickens and the flavors meld beautifully.
Stir in a splash of balsamic vinegar to add depth and brightness, then tear in fresh basil leaves for a fragrant finish.
Taste the sauce and adjust seasoning with more salt, pepper, or red pepper flakes if desired.
Serve the zucchini bolognese hot over your favorite pasta, rice, or grains, garnished with extra basil if you like.