In a bowl scrub the pork with salt and pepper then pour the soy sauce, and lemon juice. Add 1 tsp of chopped garlic and 1 tbsp. of chopped onion and mix well. Marinate for minimum of 30 minutes or overnight.
Heat oil in a deep pan or pot over medium heat and sear all sides of pork loin until brown. Set aside and save marinating sauce for later use.
Using the same pan or pot, turn down heat to low and saute onion until translucent then add garlic and cook until fragrant. Tip in tomatoes and simmer for 3-5 minutes then mash tomatoes to render juice.
Add the marinate sauce you set aside, stir then add bay leaves, sugar, and water then stir again. Place the seared pork loin into sauce and cover. Let simmer for 15 minutes and turn the pork for an even cooking.
Cover with a lid again and simmer-cook until pork is tender. When the pork is soft and tender add butter then simmer for another 10 minutes or until the sauce is thick. Remove the pork from the pan and thinly slice approx. quarter of an inch. Arrange in a serving dish and pour sauce on top. Bon appetit!