I have to tell you. The spicy shrimp (that wasn't so spicy) and cheesy orzo with roasted green beans was a hit tonight. In fact, I'm serving it for company in about a week.
A couple of tips.
1) I fill up a saucepot of water (3 cups or so) and just add the orzo into the water when it boils. Add salt to the water while it comes to a boil, but realize that the orzo really picks up the taste of the salt - so only a small palm full should do. I don't really use a tool to measure the orzo, but it is about 1.5 cups. You will drain the water and keep the orzo - so as long as the orzo has room to groove in the water, you're fine.
2) I used fontina cheese because I couldn't find manchago. Grate and keep to the side.
3) Next time, I will put the orzo in a serving bowl, then make a well in the middle for the shrimp and chorizo mixture. It is really good with the mixture served on top of the orzo. I then sprinkled the top with the cheese rather than mixing it in.
It took me less than 30 minutes from start to eating!