- In a large non-stick skillet over medium heat, heat the tomato sauce with the red pepper flakes. Keep warm.
- In a pot of boiling salted water, blanch the rapini for two minutes. Drain. Plunge into ice water for two minutes. Drain again and dry on a clean tea towel.
- In a food processor, purée the rapini, ricotta, Parmesan, eggs, and garlic. Transfer to a bowl. Add the flour and mix well. Season with salt and pepper.
- Using a three tablespoons (45 milliliters) ice cream scoop, shape the mixture into balls and place them side by side in the tomato sauce. Cover and simmer over medium-low heat for 40 minutes.
- Just before serving, top with Parmesan shavings and a drizzle of olive oil. Serve as a main dish or a side.
You can replace the rapini with two bunches of Swiss chard, stems removed and roughly chopped. You should have about 450 grams.