Bring the 2 ingredients to a rolling boil over medium-high heat. Then reduce the heat to medium-low and simmer for an additional 10 minutes or until the glaze reduces and thickens. Once the reduction can evenly coat the back of a spoon, the glaze is done. Remove from heat and let it cool.
Notes
Thin it out- If your glaze has gotten too thick, then just add a little water and heat it, stirring until it incorporates.
Don't burn it- Be careful to not scorch the bottom of the pan. If you burn the glaze, it's not salvageable. Only gently boil it to avoid overheating.
Check for doneness- See if your glaze is done by dipping a spoon in. If it coats the back of the spoon, then you've reached the right level of thickness.