Place the butter in a small saucepan & heat over medium heat until butter is a light golden brown color & smells nutty; set aside.
Bring a large pot of salted water to the boil. Add pasta, stir & cook, uncovered for 12 minutes or according to package directions, until al dente – reserve the pasta water.
Meanwhile, heat the olive oil in a large frying pan over medium-high heat. Add the chicken & cook for 7 minutes or until golden brown. Add garlic & cook for 30 seconds until fragrant.
Add the crushed red pepper & sherry. Cook for 1 minute just to cook the alcohol off the sherry.
Add sundried tomatoes & goat cheese. Add the pasta & 2 ladles of the pasta water – about 1 1/2 cups. Add the spinach, lemon juice & parsley. Stir until the pasta is coated in the creamy sauce, adding a little more hot pasta water if necessary.
Add the warm brown butter & stir to combine. Spoon the pasta into a serving dish or heated individual bowls. Sprinkle with pine nuts & extra parsley leaves. Serves 4 to 6.