Yesterday, I said that a coworker once accused me of bringing the whole kitchen to work for lunch. It was because the same week I brought my chili, I also brought tostadas. (Another one of my favorite things!) Since tostadas are really not something you can prepare ahead of time, I really did bring all of these ingredients with me and assembled them during my lunch.
Tostada shells
Vegetarian re-fried beans
Diced tomato
Shredded/chopped/ripped green lettuce (whatever!)
Diced yellow onion
Shredded cheddar or a cheddar mix
If I’m feeling fancy, I use those veggie crumbles I mentioned yesterday. These crumbles are awesome! If you prepare them in the skillet ahead of time with taco seasoning, they taste just like taco meat! Don’t use the pack of taco seasoning from the store! You can just use Chili Powder, Cumin, Oregano, Onion Powder, Garlic Powder, and a little Paprika. 
Typically, that’s the order of ingredients and you probably already have them!
I once had a taco bar dinner party and the non-vegetarians ate all my fake meat because it tasted better than the real stuff. They thought it was the beef. ;)