If making for tomorrow, should I fully cook this tonight? Or can I do the final baking tomorrow night? It has semi cooked rice, so I wasn't sure i...

The tian was great. I did as Brenna suggested and prepared it right up to the final step the night before. It actually took longer to cook than the directions, but maybe because I didn't have time to bring it to room temp before baking. And I have a temperamental oven.
Highly recommend this dish if you need to prepare a dinner party the day before....

Please know that if your par-cooked rice sits overnight, it will absorb moisture, so you final baking time may be reduced. Start by setting the timer for 10 minutes less than specified. You can always bake it longer, but it's pretty hard to unbake something that has been over baked.

Make it all in advance and bake it the night of your event, waiting to add the topping until just before baking. I think if you baked the whole thing beforehand, the texture just wouldn't be quite right the next day.