I have a double sink that is mounted under the counter. If you have this layout you can do what I do. I close the drain on one side and place the kettle in it. Then I put my faucet in the basin facing the kettle and turn the cold water on. The water fills the basin and flows over to the other side to drain. Kind of works like an immersion chiller in reverse. I get 3 gallons down to pitching temp in 30-40 minutes.
Just a word of caution if you go this route. I used to do this with my old sink because the divider between the basins was lower than the outer rim, allowing the water to flow into the other basin and drain out. Then I had a nice new stainless double sink installed and didn't notice that the divider was the same height as the outer rim of the sink. Uh oh! The one basin filled up and water started seeping out between the sink and countertop in addition to draining into the other basin, flooding my cabinets underneath. That's when I decided to buy an immersion chiller.