While some people may feel comfortable eating cold food like sliced carrots and hummus on your own non-kosher plates, other people will only eat store-bought items with certain kosher labels on disposable dishes. Unless you have the knowledge to the contrary, it is safest to assume your guests maintain the highest level of kosher observance.
- If there's a kosher restaurant, specialty shop, or caterer in the area, consider having food trays delivered to serve all of your guests. You won't have to worry about the food preparations, and can relax at your own party. Just check in with your guest to make sure they consider the shop's kosher certification valid—some restaurants offer "kosher-style" fare, but aren't actually kosher.
- Buy products at the store that have a kosher label on them and that can be served cold (for example, baked goods, crackers, cheese, deli meat, bread, etc.). Keep the products sealed in their packages until your guests arrive—that way, you can find out directly whether your guest feels comfortable using your serving utensils and dishes, or if they'd prefer to use disposables.
- Fresh whole fruit, most raw vegetables (think Persian cucumbers, cherry tomatoes, baby carrots, etc.), raw nuts, coffee, and tea are generally considered acceptable for kosher diners, even without certification.
- Either buy dairy and parve products or buy meat and parve products. Be sure not to buy and serve your kosher guest some dairy and some meat, as the Jewish dietary laws prohibit mixing dairy and meat.
- Buy disposable plates, cutlery, and cups. Anything you do to the kosher food should be done with disposable products. Use a disposable knife (or a brand new one) rather than your non-kosher knife to cut. Pick up a pack of inexpensive cutting mats if you don't want to invest in a new cutting board, and hand wash it with a new sponge.
- Before you go through the trouble of prepping anything, it's a good idea to consult with your guest first, to ensure they'd be comfortable eating whatever you plan to make. (Even raw vegetables, which are fundamentally kosher, can be controversial in some communities, so it's best to check before you prep!) Serve the food on disposable dishes.
- Keep the kosher food you bought separately from non-kosher food. When kosher food is mixed with non-kosher food, it becomes non-kosher. So don't put kosher meat and non-kosher meat together on the same plate.
- Bring your kosher guest into the kitchen. This enables them to see the kosher label on the cookie box, which increases their comfort zone. It enables them to help you, which is good for them and for you as the host. Lastly, it can ensure success in some tricky cases. For instance, only someone with experience keeping kosher might catch that the mayonnaise, while kosher, contains dairy ingredients, and can't be used in the meat sandwich.
- If your guest offers to bring something along, take them up on the offer! It's an elegant way to let your guest ensure their needs are met, and lets you off the hook a little, too!
- Most importantly, maintain the right attitude. If you are feeling resentful about having to make an extra effort, your guest will feel your resentment and have a hard time enjoying the food. Treat your guest's kosher needs like you would any other important need.