Peel and discard the outer, fibrous skin layers of banana heart until you reach the lighter, softer core.
Trim off the stem and discard. Cut into half and slice thinly.
In a large bowl, place the shredded banana heart and rock salt. Let stand for about 10 to 15 minutes or until it begins to release liquid. Using hands, squeeze to release bitter sap. Rinse very well with cold water and drain.
In a wide pan over medium heat, heat oil. Add onions and garlic and cook until softened.
Add pork and cook, stirring occasionally, until lightly browned.
Add fish sauce and continue to cook for about 1 to 2 minutes.
Add banana heart. Cook, stirring occasionally, for about 3 to 5 minutes or until releases liquid.
Add coconut milk and chili peppers. Lower heat, cover, and continue to cook for about 15 to 20 minutes or until vegetable is tender, pork is cooked through, and sauce is thickened.
Season with salt and pepper to taste. Serve hot.