Sushi lunch in Irvine
There is a Taiko restaurant nearby at Jeffrey and Walnut, southwest corner. It gets very crowded at lunch. It's decent sushi for Irvine, and fairly close to you. Sit at the sushi bar if you can.
Another choice that is closer is Sushilicious. It's not terrible, and that's about all I can say about that. It's at Irvine Center Dr and Jeffrey, northwest corner. It's sushi on conveyor belts. The color of the plate determines the price of the dish, you just pick whatever you want off the belt and eat. You can also make special requests and they do it for you. The plates range from $1.50 to $4-something. At lunch, you can pick any five plates for $10.
Going the other way, there is a Sushi Boy at Irvine Center Drive and Sand Canyon. Think of it as supermarket sushi. I work across the street, so it's a quick and easy, but otherwise a waste of a food opportunity.
There is a Wasa at the Irvine Spectrum, right across from Javier's and the Cheesecake Factory, Google puts it at 5 miles from the golf course.
Sushi is decent there, and they have other options if you have folks with you who don' tlike sushi. There is a valet by Cheesecake if you don't want to self park.