Preheat the oven to 400°F (200°C). Cut the top off the head of garlic, drizzle with olive oil, wrap in foil, and roast for 30-35 minutes until soft.

Let the garlic cool, then squeeze out the roasted cloves into a bowl.

In a saucepan, melt the butter over medium heat. Add the roasted garlic and sauté for 2 minutes.

Pour in the heavy cream and chicken broth, stirring to combine. Bring to a simmer.

Add the lemon zest, lemon juice, salt, pepper, and thyme. Cook for an additional 5 minutes, stirring occasionally.

Meanwhile, cook the pasta according to package instructions in salted boiling water until al dente. Drain and reserve some pasta water.

Add the cooked pasta to the sauce, tossing to coat. If the sauce is too thick, add reserved pasta water a little at a time until desired consistency is reached.

Serve immediately, garnished with extra lemon zest or fresh herbs if desired.