K.P.
I have a "White Chicken Enchilada" recipe that I love. Of course, you'll have to adjust it for the 150 guests you'll be having.
8 - 10 fajita sized flour tortillas
2 - 3 chicken breasts, cooked & chopped (I add pepper & other desired seasonings to the chopped chicken)
1 can chicken broth
1 sm. can chopped green chili's
1 can cream soup (mushroom, chicken or celery - your choice)
8 oz. sour cream
1 block pepper jack cheese - shredded
Mix soup and sour cream; add enough broth to desired consistency (like salad dressing, not runny & not thick). Spread enough sauce around the bottom of a 9 x 13 pan to cover bottom of pan. Lay a tortilla flat and put a spoonful of sauce in the middle. Add chicken cheese and chilie's in desired amounts. Roll or fold tortillas and place them seam side down into pan on top of sauce layer. Repeat until you have filled pan. Pour remaining sauce over all enchiladas in pan. Sprinkle any remaining cheese over top. Cover with foil back at 350 for approximately 30 minutes.
Another that I have tried - It's an enchilada casserole but I changed it up from hamburger to chicken and from cheddar cheese to pepper jack.
2 - 3 chicken breasts (boiled or baked)
1 can of cream soup (chicken, mushroom or celery)
1 can encilada sauce (mild, medium or hot - depends on how much of a kick you want)
12 - 15 corn tortillas
1 block of pepper jack cheese - shredded
Optional ingredients - chopped onion, bell pepper, black or pinto beans
Cook chicken & dice or chop. Add cream soup & enchilada sauce. Tear tortillas into bites sizes. Add tortillas and any optional ingredients to mixture. Pour into casserold dish. Top w/ pepper jack. Bake at 350 for approximately 15 minutes without the lid on.
I always add a bit of pepper to my ingredients as I like it that much. There is also another seasoning you can try. It's called "Knorr - Caldo de Tomate" Tomato Bouillon w/chicken flavor. I use the granules and add this to my "mexican dishes" as well. Just gives it a little extra flavor.
Hope one of these will help and that y'all have a great time at the 50th celebration!
K.