Summarize the following:
The sky is the limit, metaphorically, so try all kinds of things. This is a great way to pack some delicious nutrition into a compact package. You can make an entire portable salad right there inside the tortilla if you want. Try lettuce of all kinds, spinach, sprouts, chopped bell pepper (cooked or raw), broccoli (steam it lightly if you prefer), tomatoes, olives, mushrooms, and anything else you like.    {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/3\/32\/485672-5-bullet-1.jpg\/v4-460px-485672-5-bullet-1.jpg","bigUrl":"\/images\/thumb\/3\/32\/485672-5-bullet-1.jpg\/aid485672-v4-728px-485672-5-bullet-1.jpg","smallWidth":460,"smallHeight":308,"bigWidth":"728","bigHeight":"487","licensing":"<div class=\"mw-parser-output\"><p>Image by: Uploader<br>\nLicense: <a rel=\"nofollow\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by\/3.0\/\">Creative Commons<\/a>\n<\/p><\/div>"} While they're not as frequent an addition to sandwiches or salads, you may find you like the bit of sweetness or tartness that fruits add. Try bits of pear or apple, grapes, raisins, or any other fruit you think might taste good with your combination of fillings.

Summary:
Add veggies, pile them high. Try fruits, fresh or dried.