In a medium-sized bowl, toss pork with 1/2 Tablespoon balsamic vinegar and a pinch of salt.
1 lb. pork tenderloin, trimmed of excess fat and silverskin removed, cut into 1/2" pieces, 2-1/2 tbsps balsamic vinegar, kosher salt
In a another small bowl, combine remaining 2 Tablespoons vinegar, soy sauce, cornstarch, ketchup, 3 tablespoons sugar, 1/3 cup water and half teaspoon kosher salt.
2 tsps low sodium soy sauce, 1 tbsp cornstarch, 3 tbsps ketchup, 3 tbsps granulated sugar, 1/3 cup water
Heat 2 Tablespoons oil in a large skillet over high heat. Add the pork and slowly stir until it turns mostly opaque, about 2 minutes. Remove pork with a slotted spoon and transfer to a plate. Discard oil and wipe out the skillet.
3 tbsps peanut oil
Heat the remaining 1 Tablespoon oil in the skillet, then stir fry the garlic with a pinch each of salt and sugar (only 15 seconds or it will burn). Add carrots and scallions and "stir-fry" until crisp tender, 2 minutes. (If mixture seems dry add a little bit of water, just a little.) Add pork, snow peas and soy sauce mixture; stir until the pork is cooked through and the sauce is thickened, about 3 minutes.
3 cloves garlic, minced, 2 carrots, thinly sliced, 3 scallions, cut into 1/2" pieces, 3 cups snow peas, cut in half