To play it safest, you might wish to serve a dairy meal. (Finding kosher meats would be trickier esp. in regions with a low Jewish population, so best to avoid altogether.)
This means go vegetarian! Dishes like tuna salad or egg salad. Pasta and pasta salads are ok , too. Or, have an omlette night at your house! All fruits and vegetables are fine - no doubt. If you serve fish, fish is considered “neutral” (parve) and can be dairy. Flounder or salmon is a safe bet. Absolutely no shellfish whatsoever! Do NOT stuff the flounder with crab meat, either! Lox (smoked salmon) or herring is a nice treat, too. Smoked whitefish or whitefish salad is delicious, too! Small whitefish are known as “chubbies”, and is very popular with Jewish people…if your guest likes fish. Although, many of these suggestions can be expensive.
If you serve breads, make sure there is no animal fat in them, such as lard, although lard is less popular today. Cheeses are mostlikely ok, although some Jews argue about a certain enzyme used in various dairy products. I wouldn’t sweat this…this is more of a personal decision by your guest. (If you want to cover all bases, you can show him the labels of any products you serve, if he’s really concerned, but I doubt it.)
Lastly, you can serve gefilte fish (packaged in bottles or jars) which is a mix of ground-up whitefish and pike. Pressed into balls (for finger food eaten with a toothpick) or oblong “mounds” (for lack of a better word), the latter may be served over a lettuce leaf. Horseradish is the dip of preference to spice up these kinda bland, but still tasty, fish balls. Also, ask your grocer for “Tam Tam” crackers which complement the gefilte fish, or can be used to make small sandwiches for fish spreads such as whitefish or a herring salad.
Humus (groud-up chick peas into a paste, or fried into balls) is good, too. You may be familiar with falafal (sp?), no? This is basically a pita containing balls of fried, ground-up chickpea rolled into a ball and stuffed with lettuce and diced tomato and maybe diced onions - whatever you prefer…almost like a vegetarian gyro! Bordering in the Greek’s style of eating, it is a germain to the Middle East/Meditaranian region.
Watch out for products which seem harmless, like cream of brocolli soup which has a chicken or beef broth base. Also, make sure vegetable soup IS vegetarian vegetable soup. Make sure baked beans are vegetarian baked beans (i.e.: not in a sauce containing a hidden pork product in the sauce, typ.)
As for dessert: Stay away from desserts containing gelatin such as all jellies, Jello, or marshmallows. Jams and preserves are ok. The kosher form of such gelatin-containing foods are hard to find depending where you live. Fruit salad is fine, but avoid marshmallows such as in Watergate salad or ambrosia, I believe. Again, watch for lard in baked goods.
Oh, one last note! While fresh grapes are fine, avoid all grape products such as wines, grape juice, and grape jelly, jam, or preserves. This is because, supposedly, grapes are considered holy and follow even stricter laws of “kosher”.
Don’t let all this detail scare you off! There are symbols on the package to guide you: Except for fresh fruits and fresh veggies, the general rule is to look for items marked with a “(U)” symbol (pronunced as “OU”). This means the product has been produced under obseravtion of a rabbi belonging to the Union of Orthodox Rabbis. There are many other symbols such as an (K) (pronounced “OK”). A “K” by itself it often debated. Often, the food manufacturer puts this symbol on their product to say, in their opinion, the product is kosher. I think I once read there are now over 100 symbols to mark a food “kosher” representing various local and national groups of rabbis!
I think that covers it! Whew! (Now, why bother eating after all that, right?) Good luck! - Jinx