Layer a pint-sized mason jar with cucumber slices, onions and garlic. Combine the remaining ingredients in a non-reactive saucepan. Bring to a boil and simmer for 4 full minutes to wake up the spice flavors. Allow to cool to room temperature. Slowly and gently pour the pickling liquid over the onion and cucumber slices, filling to the top of the jar. Refrigerate for at least 24 hours before consuming.