Prepare the leeks. Cut off the tough, dark green parts of the leeks and discard them (you can use them to make vegetable stock). Then, slice the leeks in half lengthwise and rinse them well under cold water to remove any possible dirt. Cut the leeks into ½-inch (1.3 cm) slices (discard the bottom roots) and set aside.

Sauté the onion. Heat the oil and vegan butter in a non-stick skillet over medium heat. Once the butter has melted, add the diced onion and sauté for 2-3 minutes, or until it is soft and golden brown.

Add the leeks. Add the sliced leeks to the skillet and season with salt and ground black pepper. Sauté for about 2 minutes.

Cook covered. Next, add the water and cover the pan with a lid. Cook over medium heat for about 25 minutes, or until the leeks are tender and have softened. Check regularly to ensure the leeks do not burn. If needed, add a few extra tablespoons of water.Remove the lid and sauté for an additional 3-5 minutes, or until the leeks just start to caramelize and slightly stick to the bottom of the skillet. Keep an eye on them to make sure they don’t burn.

Cook the pasta. Once the leeks are almost cooked, bring a large pot of salted water to a boil and cook the pasta according to the package instructions. Save about ¼ cup of the pasta cooking water.

Combine. Drain the cooked pasta and add it to the skillet. Stir to toss the pasta with the melted leeks. Add the reserved cooking pasta water and cook for one more minute. Taste and adjust the salt as needed, and serve immediately!

You can store this leek pasta in the refrigerator for up to 3 days. Reheat in a non-stick skillet over medium heat for a few minutes.