First, prepare your banana heart by peeling off all the dark purple outer layers until you reach the pale white core. Cut off the stem, then slice the heart in half lengthwise. Slice each half into very thin pieces, about as thick as a peso coin. Put all the sliced banana heart in a large bowl and mix with 2 tablespoons of rock salt. Let this sit for 15 minutes. After 15 minutes, squeeze the banana heart firmly with your hands to remove the bitter liquid, then rinse well with cold water until the water runs clear.

Heat your pan over medium heat and add oil. Once hot, cook your chopped onions until they turn clear, about 2-3 minutes. Add your minced garlic and cook just until you can smell its aroma, about 30 seconds. Add your diced pork belly and cook until the meat turns light brown, stirring occasionally, about 5-7 minutes.

Add fish sauce and stir everything for one minute. Now add your prepared banana heart and stir to mix well with the pork. Pour in your coconut milk and add the chili peppers if you're using them. Lower the heat to the lowest setting - this is very important so your coconut milk won't separate.

Cover your pan and let everything cook gently for 15-20 minutes, stirring every few minutes to make sure nothing sticks to the bottom. Your dish is ready when the banana heart is tender when pierced with a fork, but still has a slight bite to it, and the sauce has become creamy and slightly thick. Taste the sauce and add salt and pepper if needed. The sauce should be rich and creamy, perfect for pouring over hot rice. Serve while hot.

Remember: If your sauce starts to separate or look grainy, your heat is too high. Keep it at a very gentle simmer throughout the cooking process. Your patience will be rewarded with a perfectly creamy sauce.