Slice the zucchinis halfway through lengthwise, careful not to pierce through the center. Spiralize on Blade A to yield chip slices. Set aside.

Heat the olive oil in a large pot over medium-high heat. Once the oil is shimmering, add the garlic, red pepper flakes, and onions, stir for 1 minute to soften onions and then add in the zucchini. Stir well and let cook for 3-5 minutes, tossing the zucchini occasionally, unit zucchini begins to soften.

Add the white beans, tomato sauce, broth and simmer for 5 minutes.

Stir in half of the basil, the spinach, and season with salt and pepper. Let cook for 2-3 more minutes or until the spinach wilts.

Divide stew into bowls and garnish with remaining basil and Parmesan cheese, if using.