Trim Brussels sprouts and cut in half through the stems, cutting the large ones into quarters.
Heat the air fryer to 400 degrees Fahrenheit.
Place Brussels sprouts into the air fryer basket, add salt and drizzle on a little oil, about 1 tablespoon. Fry Brussels sprouts for 15 minutes, stirring occasionally.
Add in the garlic, and then fry until garlic is golden brown, another 2-4 minutes.
In a small saucepan, bring the balsamic vinegar to a simmer. Continue simmering another 2 to 3 minutes, until it has thickened to a syrup-like consistency, but don't allow it to burn. Remove from heat and whisk in the remaining oil, the lime juice and the soy sauce.
Transfer the Brussels sprouts to a plate and drizzle the balsamic vinegar on top. Add more lime juice or salt to taste. Enjoy!