Preheat your oven to 400°F (204°C). Slice a garlic bulb in half, drizzle it with olive oil, and wrap it tightly in aluminum foil. Place the foil packet on a baking sheet and roast for about 45 minutes, or until the garlic is soft and fragrant.

Once the roasted garlic has cooled slightly, carefully unwrap the foil and squeeze the cloves out into a bowl. Use a fork or a mortar and pestle to mash the roasted garlic into a smooth paste.

In a large skillet, melt the butter over medium-high heat. Add the creamy mashed garlic along with the fresh rosemary and thyme, crushed red pepper flakes, kosher salt, and black pepper. Cook for about 2-3 minutes, stirring frequently.

Gradually whisk in the heavy cream, starting with 1/4 cup at a time. Keep whisking for about 5 minutes until the sauce thickens.

Stir in the grated Parmesan cheese, ensuring it melts into the sauce. Cook for an additional minute, stirring constantly until the sauce reaches your desired consistency. Adjust seasoning as needed.