In a saucepan, combine Liquid Aminos, 1 cup water, ginger, garlic, brown sugar, and agave. Bring to a simmer. Mix ¼ cup water with cornstarch, and pour into the simmering sauce. Stir continually until sauce turns from opaque and milky to clear and shimmering. Remove from heat. Cool to room temperature before storming in the fridge for up to a week.