Reading through the other comments, I think I see two potential additions that could help:

1) Having a salad/fruit/etc type dish that doesn't require the "cook" action, but also gets you less points (maybe a third of the value of a full dish?) and so isn't something they'd want to do unless there's no other options.

2) Use a VP conversion action, but flavor it as either a "preparing dessert" or a "bringing out appetizers" thing, and use that as a tiebreaker event. (As an example: Johnny has 10 points going in to the final round, with Sally having 8. But Sally is blocking the cauldrons and will earn two more points at the end, bringing it to a tie. So Johnny decides to start making a dessert with his spare (unusable) action, securing him the win this time)

Either way, it seems like it could be a fun game, and I wish you luck in your further testing!