Lunch in Corona???
I work in the area and there are lots of places we go for lunch. My favorite Mexican place in the area is Rodrigo's (Main & Parkridge), on the other side of the shopping center where Rodrigo's is there is a Cuban place that just opened not too long ago, we've been there a couple of times and thought it was good. We also really like Isabella's, a little hidden Italian place in a shopping center with a Stater Bros. and a Rite-Aid, it's like an oasis away from the craziness and the food is great. Mill Creek has terrific BBQ and ir right off the 91, you can see it from the freeway. Bangkok Bay (on Main St.) has great Thai food. There's a few suggestions for you, sorry I don't have all the addresses!