Find Barilla tortellini on your supermarket shelf. It comes in 8 oz and 24 ounce packages in the dry pasta section. Measure out 4 ounces for the trail.
Go to Kentucky Fried Chicken / Taco Bell. Ask to buy 2 packets of Newmans "Family Recipe Italian" or "Parmasean & Roasted Garlic" salad dressing single-serve packets. (Either a buck, or free, if someone is in a good mood.)
On the trail, add about 2 cups of boiling water to the cozied Tortellini.
Fifteen minutes later drink off the excess liquid and add one packet of Dressing.
I augment with Just Vegies mixed vegetables (for color) and pre-measured parmesan cheese (for taste).
There are tubes of tomato paste out there, but I find an oil based dressing is a much better option.