Place the can of coconut milk in a medium saucepan and bring to a gentle simmer over medium-high heat. Stir occasionally to prevent scalding.
Once the milk is hot, whisk in the curry paste, soy sauce, lime juice, brown sugar, and minced garlic clove. Keep whisking over medium-high heat for 15-20 minutes until the sauce is thick enough to coat the back of a spoon and reduced by almost 1/2. The longer you cook it, the thicker it will be! You can also thin out the sauce with a little water/vegetable broth if you want it thinner in consistency.
While this sauce is delicious over just about anything, I love it with steamed vegetables, rice, and pan-fried tofu.
Notes
*Depending on the curry paste that you use, you may need to add a minced Thai pepper for more heat. I used a vegan brand that I got at my local Asian market which had a lot of heat! However, I made the dish again using the Thai Kitchen brand and it needed more heat. I added a finely minced Thai pepper to add heat and it was great! So, adjust as needed.