I made a sauce out of 1/3 c ketchup, 2 Tbsp mustard and 2 Tbsp brown sugar instead of the tomato paste and water they use.
Also, my kids won't eat mushrooms but I had vegan crumbles so I used those instead. Added a little soy sauce for umami. It was really yummy! But very crumbly. Maybe bc I didn't cook it as long as the recipe said. But it had reached temp at 30 min so I took it out.