Best way to prepare multiple pans of lasagna

That’s a very clear “it depends”.

Theoretically you can just triple all ingredients, cook the sauces and assemble factory line style. One big batch cooked, one round of washing up.

However, there are a few details to consider:

• Are your pots and pans large enough? Also consider the ratio of surface area to volume, this can affect evaporation and change how long a sauce needs to reduce or reach the desired thickness.
• Can you handle the amounts comfortably? For example, making a large quantity of roux needs quite a bit of strength and quick action or you may end up with uneven texture and lumps.
• Does it matter if the cooking times are different because of the difference in volume? For a regular bologna it’s probably not an issue (the mirepoix would fall into the upper category again), if you are working with vegetables that are supposed to keep a bit of a bite, it may. You need to cook to the desired doneness, not going by the time in your recipe.

If the caveats above are not a problem for you and your recipe, go ahead and do a large batch.