01 -
Toss cubed butternut squash with 1 tablespoon of olive oil and salt. Spread on a baking sheet and roast at 430°F for 25 to 30 minutes, stirring halfway, until tender and caramelized.
02 -
Heat 2 tablespoons of olive oil in a pan over medium heat. Sauté garlic gently, stirring frequently to prevent burning. Add chili flakes and cook for another 1 to 2 minutes.
03 -
Boil spaghetti according to package instructions, cooking 1 minute less than recommended for al dente texture. Drain well.
04 -
Mash half of the roasted squash with a fork and add it along with the remaining chunks to the pan with garlic and chili. Stir to combine.
05 -
Add drained spaghetti and washed spinach to the pan, mixing gently until spinach wilts and ingredients are evenly combined.
06 -
Adjust seasoning with lemon juice, salt, pepper, and extra chili flakes if desired. Drizzle additional olive oil if preferred. Serve immediately topped with chopped walnuts and lemon zest.