Spaghetti with Spinach and Sun-Dried Tomato Cream Sauce in 30 Minutes

Ingredients

• 12 oz (340 g) spaghetti
• 5 oz (140 g) fresh baby spinach, roughly chopped if large
• 1 tablespoon kosher salt, for the pasta water
• 1 tablespoon oil from a jar of oil-packed sun-dried tomatoes
• 1/2 cup (65 g) oil-packed sun-dried tomatoes, drained and thinly sliced
• 1/2 small yellow onion, thinly sliced
• 4 cloves garlic, minced
• 1/4 teaspoon crushed red pepper flakes, plus more to taste
• 1/2 teaspoon fine salt, plus more to taste
• 1/4 teaspoon black pepper
• 1 cup (240 ml) low-sodium vegetable broth
• 3/4 cup (180 ml) heavy cream
• 1/2 cup (45 g) finely grated Parmesan cheese, plus more for serving
• 1 tablespoon unsalted butter