I actually did this in the field over the weekend for dinner one night. I had cooked (canned), dehydrated corn and carrots in a bag, along with some celery flakes from the seasonings aisle. I put 7 ounces of water in the bag at approximately 2-3 hours before dinner. At 30 minutes before dinner, I added the ramen seasoning packet and the noodles. I broke up the noodles and kneaded it all around to mix and rehydrate faster. Last, I mixed in the tuna packet and ate it. Honestly, I really didn't care for the celery much with this particular mix. If I did it again, I'd probably leave it out. But, it was filling and good trail nutrition.

And, on a side note, I also made GORP + M&Ms for this trip, and man, did I ever over-estimate how much of that stuff I would eat! I came home with over half of it.