I knew it.
Yes, it's during the fight to the death between Anakin Skywalker, aka the newly named (though yet to be cooked and cyborged) Darth Vader, and Obi-Wan Kenobi. About partway through the fight, they try to use the Force against each other simultaneously with those gestures. At first, they have a little tug-of-war impasse, before blasting each other away.
Okay, someone else try.
"What have you been doing since you stole that antique TARDIS of yours, since you first landed on Skaro? Shouting 'Look at me!!! I'm not fighting a war!', while you battle the Daleks all the way through space and time."