in medium sauce pan cook pasta according to directions on pasta. I usually use the spiral or rigatoni pasta. Drain and set aside.
in large skillet brown hamburger, adding the mushrooms and half the onions. Drain and add to large stock pot.
add the tomato soup, black olives, tomato sauce, pasta and the rest of the onions, and pepperoni. Mix well. over low heat, heat until warmed thoroughly. this goes well with garlic bread and parmesan cheese. I am not used to measuring I usually cook by taste and sight so feel free to tweak the amounts of the ingredients to your taste. I also sometime add Italian seasoning to the hamburger mixture while it is cooking. Also if you wants you could add the pepperoni to the pasta when it is almost done cooking, this flavors the pasta and I thought it tasted great when I tried it.