Chop your meat into small pieces, and prepare the onion, ginger, garlic, and lemongrass (unless using frozen).
Heat the oil in a large pan over medium heat, add the onion and cook for 3-4 minutes, until soften but not yet browning.
Turn heat to medium-low, and then add half of each the garlic and ginger, letting it cook for 30 seconds before adding in the chicken.
Add the chicken, then stir to make site it's all evenly-coated in oil, and then arrange it in a thin layer in your pan, cooking it for about 6 minutes, stirring occasionally. This is the perfect time to chop your lime leaves, if using them (don't forget to remove the stems).
Once the outside of the meat has begun to cook, add the lemongrass and the rest of your garlic and ginger, stirring everything until well-combined. Keeping the heat on medium-low, cook for about 8 more minutes, focusing on letting the meat cook and not letting any of the sauce stick to the bottom of the pan. If anything begins to stick, add water 1 tablespoon at a time until everything forms a sauce again.
Once the chicken is mostly cooked, there should still be a watery sauce underneath. Add the sugar and salt to the mix, turn the heat up to medium-high, stirring everything well and cooking for 2-3 more minutes, until the sugar begins to caramelize. Be careful of splattering oil!
Turn off the heat and add the lime juice, stirring well.
Sprinkle a bit of lime leaf on each serving after you plate it, adding any more salt you need once you've given it a taste. Serve with rice or garlic-infused veggies for a low-carb, low histamine dinner!