Pour the coconut milk into a small saucepan over high heat. When it reaches a gentle simmer, add the peanut butter, curry paste, fish sauce, lime juice, brown sugar, and garlic. Whisk and keep on high heat for 15 minutes or until the sauce has reduced and thickened.

Add the peanuts and simmer for another 5-10 minutes. When the sauce coats the back of a spoon, add small amounts of broth or water and whisk to adjust consistency depending on how you will use it and how thick you want it. If the sauce separates, whisk vigorously to smooth it out again.

Serve over rice, noodles, chicken, fish, vegetables, or any other way that sounds good to you! Top with crushed peanuts and scallions.