Slice the onions. Start by peeling the onions. Next, slice them into ⅛-inch thick (3 mm) slices.

Sauté. Heat the oil and butter in a large skillet over medium heat. Once the butter has melted, add the sliced onions and a pinch of salt. Sauté for 5-6 minutes, stirring regularly, until they begin to turn a light golden brown color.

Season. Add the ¼ teaspoon of salt and the sugar, and sauté for another 25-30 minutes, stirring occasionally, until the onions are caramelized and have a deep golden brown color.

Deglaze. Once the onions are done, deglaze the skillet with 2 tablespoons of water to release any small particles that may be stuck to the skillet. This will help extract even more flavor! Remove the skillet from the heat, keeping the onions inside, and set aside.

Make the cashew cream. Drain the soaked cashews and transfer to a blender. Add the water, vinegar, salt, and nutritional yeast. Blend on high speed for 20-30 seconds or until smooth. Set aside.

Cook the pasta. Bring a large pot of salted water to a boil and cook the pasta according to the package instructions. Drain and transfer the cooked pasta to the skillet with the caramelized onions.

Combine. Pour in the cashew cream and toss to coat using a pair of tongs or two spatulas. Place the skillet back on the heat and cook for 3-5 minutes over medium heat, stirring frequently. If the sauce appears too thick, dilute it with some water.

Serve. Taste and adjust the saltiness if needed. Garnish with chopped parsley or basil, and a sprinkle of black pepper.