Heat the olive oil in a non-stick large skillet. Add the onion and saute for a few minutes.
Add the garlic and stir. Add the orzo pasta and stir for a few minutes until the onion is translucent.
Stir in the diced tomatoes and water, and let the orzo simmer for a couple of minutes. Add the oregano and basil and continue to simmer for about 10-15 minutes until the orzo is tender and most of the liquid is absorbed. You might need to add a bit more water during cooking if the liquid is gone before the orzo is done.
Sprinkle the feta cheese on top of the orzo, let the cheese warm a minute or two, and serve.