Serving pasta in a buffet-style setting is challenging; you need a chafing dish to keep it warm. While the chafing dish does a great job of ensuring hot pasta on demand, the constant heat can also dry the pasta out and make the pasta stick together. Professional-catering dishes have a water reservoir that steams the food and keeps it moist. If you do not have a high-end chafing set, you can still keep your cooked pasta from sticking together.
Cook the pasta until it is al dente -- soft but with a little resistance. It will continue cooking in the heat of the chafing dish so you do not want to overcook it.
Set up your chafing dish. Light the Sterno underneath.
Pour 1/2 inch of room-temperature water into the chafing dish. Cover the dish and let the water heat.
Drain the cooked pasta in a colander. Thoroughly rinse the pasta in cold water for five minutes. Rinsing stops the cooking process and it removes excess starch -- which can make the pasta sticky -- from the surface.
Drizzle a small amount of olive oil on the pasta. Toss the pasta to coat it evenly with the oil. The oil adds moisture and also prevents the pasta from sticking.
Add the pasta to the water in the chafing dish. Replace the cover. The water in the chafing dish will steam the pasta and keep it moist.
Stir the pasta periodically so that the pasta on the bottom does not overcook. Add more water if it evaporates ad keep the chafing dish covered between uses.