Cool skillet for 1-2 minutes, then return to low heat and add ¼ cup butter. Once butter melts, add 2-3 minced garlic cloves and sauté 30-60 seconds until fragrant.
Add 1½ cups low-sodium chicken broth. Stir, scraping the bottom, and simmer on low until reduced by about ¼.
Move skillet to a cool burner for 30-60 seconds. Slowly whisk in 1 cup heavy cream into the reduction.
Gradually whisk in 1 cup grated fresh Parmesan until melted and incorporated. Return skillet to low heat. Whisk gently for about 1 minute until heated through.
Stir in ⅔ cup sun-dried tomatoes, 2 teaspoons dried oregano, and ½ teaspoon crushed red pepper flakes. Taste and adjust seasonings. If the sauce is too thin, stir in 1 tablespoon of reserved pasta water and simmer for 1-2 minutes; repeat if needed.