Bring a large pot of salted water to a boil. Add the farfalle and cook 2 minutes under al dente. Reserve ½ cup of the cooking water and then drain the pasta.
As you wait for the pasta water to boil, cook the onions and cabbage.
Heat 1 tablespoon olive oil in a large skillet over medium heat. Add the onion and cook, turning occasionally, for 5–7 minutes until softened. Season with salt.
Add 1 tablespoon olive oil and the chopped cabbage to the skillet. Turn the heat to medium-high. Cook, turning often, until it softens and begins to char around the edges, about 6–8 minutes. Turn often to keep the onions from burning. Add a generous pinch of salt and reduce heat to medium-low.
Taste the cabbage and add more salt if needed. Add the minced garlic and cook for 1–2 minutes until fragrant.
Add the walnuts, brown sugar, cooked pasta, minced parsley, and a pinch of paprika. Pour in half the pasta cooking water and toss to coat. Cook for 3-4 minutes until the pasta is completely cooked; add the remaining pasta water if needed. Taste and season.
Divide the pasta between bowls and garnish with more parsley if you like. Enjoy!
