Heat 1 tablespoon extra virgin olive oil in a wide pot over medium heat. Add the onion and diced fennel and sauté for 8–10 minutes or until both begin to soften and darken around the edges. Season with salt and pepper.

Melt the butter into the onion and fennel. Once bubbly, add the tomatoes and cook for 5 minutes until the skins begin to split. Add a sprinkle of salt.

Turn the heat to medium-high. The tomatoes and aromatics will begin to sizzle loudly. Stir in the garlic and crushed red pepper and cook for 1 minute. Pour in the water or stock and bring it to a boil.

Taste and season with salt and pepper. Reduce heat and simmer for 15 minutes, adding more water as needed if the sauce begins to stick.

Bring a large pot of water to a boil. Add a generous pinch of salt.

Right before cooking the gnocchi, finish the sauce. Add the chopped kale to the sauce. Cook for 3–4 minutes until it just begins to wilt. Add the lemon juice and season again to taste.

Add the gnocchi to the pot of boiling water and cook for 4–5 minutes or until the gnocchi float to the top. Scoop out ½ cup of the gnocchi cooking water and then drain the gnocchi.

Turn the heat on the sauce to medium. Stir the grated Parmesan cheese into the sauce. Once it melts, add the cooked gnocchi and half the cooking water. Cook for 1–2 minutes, turning occasionally, until the gnocchi is well-coated with sauce. Add the remaining pasta cooking water if needed. Turn off the heat.

Transfer the gnocchi and sauce to a large serving platter. Garnish with a pinch of grated Parmesan and scatter fresh basil leaves and reserved fennel fronds on top. Enjoy!