J.B.
Try going to this website. www.allrecipes.com I love this website. You can click on "Ingredients" at the very top middle part of the page. Then you type in the ingredient that you want "Onion Soup Mix" and in the other column you type in the ingredient that you don't want "Ketchup" and then under that there is a spot for Keyword so you type in "Meatloaf". This will bring up every recipe that falls under those requests. Plus people that made the recipes rate it so you know if it tastes good or not.
I found two that would work for you probably. If you don't want to do all the above then type in "Cheesy Meatloaf" or "Eileen's Meatloaf" at the top search box.
You can set up your account and save all the recipes that you like into your recipe box. I always turn to this website when I want something new. I love reading the comments by the other people because sometimes they suggest a minor change in the recipe such as decrease an item or add another item and it makes the recipe much better.
Enjoy!!