Warm your pan over medium heat for about 5 minutes. (veganinsanity.com)
Also, keep the heat a little lower than medium to get the mustard seeds ready, since adding them to too warm a pan can send many of them flying around the kitchen. (marthastewart.com)
And I definitely prefer using it to top off an already warm pan rather than moving a hot pan to the sink and back. (maisondepax.com)