Prepare the Pork: Slice the pork tenderloin into strips, keeping in mind that they will slightly shrink during cooking. Season them with salt.
Sear the Pork: Place a large skillet over medium-high heat and coat the bottom of the pan with enough oil, due to the lean nature of pork tenderloin. Once hot, space out the meat in the pan and sear each side. Transfer them to a plate.
Sear the Bell Peppers: Add more oil as needed and sear the bell peppers until slightly charred and tender-crisp, about a minute. Transfer them to a plate.
Sauté the Aromatics: Reduce the heat to medium and sauté the garlic and onions until they turn translucent, adding more oil if necessary.
Brown the Tomato Paste: Add the tomato paste and cook it for a few minutes, stirring constantly, until it caramelizes and darkens in color.
Combine Ingredients and Simmer: Add the meat, bay leaves, 2 cups of water, chicken base, fish sauce, sugar, and ground pepper to taste. Stir together, while scraping the browned bits on the bottom of the pot. Let it come to a boil on medium-high heat.Cover and reduce the heat to medium, simmering until the pork tenderloin becomes tender, about 20 minutes. Add more water as needed to maintain the desired consistency.
Add Bell Peppers and Peas: Add the bell peppers and green peas, cooking them briefly just until heated through to retain their vibrant colors. Taste the sauce and adjust as needed. Turn off the heat.
Notes
Pork: I used pork tenderloin sliced into strips for quicker cooking. It is one of the leanest and most tender cuts. You can also use pork loin, belly, or shoulder for more flavor and moisture; adjust cooking times accordingly. If you prefer, chicken is also an excellent alternative.
Green Peas: Use fresh or frozen peas, being careful not to overcook them to maintain their vibrant color and texture. Canned peas can be a suitable substitute if that's what you have available.
Tomato Paste: A rich, concentrated form of tomatoes that gets a nicely caramelized tomato flavor. If you want to use tomato sauce instead, reduce the amount of water in the recipe.