Our kitchen is simply a fold-down table on the side of my trailer.
What came from a simple idea is extremely useful. Sometimes you're on terrain where it's just impossible to set a table up. Only thing I plan to add next year is a bar on one side to hold a hand towel and a bar on the other to hold a papertowel roll. I'd also like to look into some sort of stainless steel sheet for a countertop or maybe even that starboard stuff everyone is talking about a few pages back. Something that wipes down easier and is durable.
For a sink we just use a big rubbermaid container that we hold all of our kitchen supplies and cutlery in.