Melt the butter in a medium saucepan over medium heat until foamy, about 1 minute.

Pour in the heavy cream, bring to a gentle simmer, then reduce heat to low and cook 2 to 3 minutes until slightly thickened.

Remove the pan from the heat, add the parmesan, and whisk until smooth and fully melted. Taste and add a small pinch of salt if needed.

Pour the sauce over your hot cooked meat right away and serve immediately.