Answer:
Ketchup's slightly less popular brother.
You throw away the outside, eat the inside, and throw away the inside. What is it?
This is a Japanese food consisting of cooked vinegared rice sushimeshi combined with other ingredients, usually raw fish or other seafood
You’ll find me in a soup, in a burger, in a pizza, I am green when raw and red when ripened and ready to become a condiment.
I'm a food made of flour, water, and yeast or another leavening agent, mixed together and baked. You need me to make a sandwich.
What is round, has a twin, and sees more than most?