Grate the zucchinis on the coarse side of your box grater until you have about 2 cups of shredded zucchini. Set aside.
Heat a splash of olive oil in a deep skillet over medium heat until shimmering and fragrant.
Add the finely chopped onion and minced garlic to the pan. Sauté for about 3 minutes, stirring often, until the onion becomes translucent and the garlic smells fragrant.
Toss in the grated zucchini, stirring to combine. Cook for 5-7 minutes, allowing the zucchini to soften and release some moisture, which will make it glossy and slightly shrunk.
Pour in the crushed tomatoes and season with salt, pepper, and a pinch of red pepper flakes. Stir well to incorporate all flavors.
Reduce the heat to low and let the sauce simmer uncovered for 15-20 minutes, stirring occasionally, until it thickens slightly and the flavors meld together.
Taste and adjust the seasoning with additional salt, pepper, or red pepper flakes if desired. The sauce should be glossy and coat the back of a spoon.
Finish by stirring in chopped fresh basil or parsley for a bright, herbal note.
Serve the zucchini bolognese hot, spooned over pasta or your favorite grains, and enjoy a nourishing, vegetable-packed meal.