I wouldn't have thought of a casserole, because it seems like you need so much more food that way...besides all the foods are mixed together & if someone doesn't like one of the ingredients, they're out of luck. Also, to me a casserole is a "home-y" food - not something I think of for guests. (and I think this situation sort of applies
)
But how about Chicken Stew? That wouldn't be tomato based (at least not the way I make it).
The other thing I thought of was to make a beef roast & shred it for sandwiches.
Drip Beef Sandwich
3-4 lb roast
2 c water
4 tsp instant bouillon
3 tsp garlic powder
1 Tbl oregano
2 Tbl seasoning salt
1 tsp coriander
1 tsp chili powder
½ tsp cardamom
1 tsp Worcestershire sauce
to taste Kitchen Bouquet
a few drops of Liquid Smoke
Put roast, water and all spices in crock pot and cook all night. Remove roast and pour juices in a bowl. Put the bowl in freezer until fat hardens. Remove fat by skimming off the top.
Pour juices back in the crock pot. Shred roast and put back in crock pot. Cook on low until ready to serve.