Ravioli with radicchio and sage

Ingredients:

• 80 g unsalted butter
• 1 small onion, finely chopped
• 2 heads of radicchio (about 250g each), cut into 2cm pieces, core removed
• 340 g of cheese ravioli
• 2 tbsp fresh sage leaves, chopped

Preparation:

1. In a large wide saucepan, bring water to a boil and add salt.
2. In a large skillet over medium heat, melt 2 tablespoons of butter. Add the onion, season with salt, and cook, stirring occasionally, until softened, about 4 minutes.
3. Increase the heat to medium-high, add half the radicchio, season with salt and pepper, and cook, stirring and turning, until tender, about 5 minutes. Transfer everything to a medium bowl.
4. In the same skillet, melt 2 tablespoons of the remaining butter, add the remaining radicchio, season with salt and pepper, and cook, stirring and turning, until tender, about 5 minutes. Return the first batch of vegetables to the skillet, stir to distribute evenly, remove from the heat, and cover to keep warm.
5. Meanwhile, add the ravioli to the water, stir well, and cook until tender, about 6 minutes. Discard 1/3 cup of the cooking water, then drain the ravioli in a colander.
6. Melt the remaining 1 tablespoon of butter in the same pan you cooked the ravioli in over low heat. Add the sage and cook, stirring, for about 1 minute. Add the ravioli and toss to coat with the sage oil. Add the vegetables and mix well.
7. Add 3 tablespoons of the reserved ravioli cooking water and toss to coat. The ravioli should be well-oiled; if they seem dry, add a little more water. Season with salt and pepper to taste.
8. Divide the ravioli among four warm plates and serve.