First, a large pot of salted water is brought to a boil. The fettuccine is cooked according to the package instructions until al dente, then drained and set aside.
Meanwhile, a large skillet is heated over medium heat. Butter and olive oil are added, allowing the butter to melt completely.
Next, the minced garlic is sautéed for about 30 seconds until fragrant. The heavy cream and whole milk are poured in, and the mixture is stirred to combine.
The sauce is brought to a gentle simmer, and Parmesan cheese is gradually whisked in until smooth.
Italian seasoning, salt, black pepper, and red pepper flakes (if using) are added for enhanced flavor.
The cooked chicken is gently folded into the sauce, followed by the steamed broccoli.
The drained pasta is tossed into the creamy sauce, ensuring it is fully coated.
Finally, the dish is garnished with fresh parsley and served warm.