Hidden in a multi-ethnic strip mall on Harbor Boulevard in Costa Mesa, Moscow Deli is a tiny slice of a cuisine underrepresented in Orange County. It's run by a pair of the nicest women ever to emigrate from Mother Russia, and the menu is full of a taste of home—if your last name ends in "ski." They've recently branched out, putting far more emphasis on hot foods and the thick, meal-in-a-bowl soups for which Russian cuisine is noted. Try the solyanka, a funky, rich, sour soup of meat and pickled vegetables, or a plate of stuffed cabbage and a huge potato pancake. Sandwiches are where Moscow Deli's food service started, and they're still a great bet. Try the Odessa, piled high with thinly sliced sausage, vegetables and eggplant spread on sour rye. Desserts are everywhere, from the rich Russian ice cream in the freezers to the poppyseed pierog under glass to the outstanding syrniki, pancakes made almost entirely of farmers' cheese and raisins, served with the inimitable Russian sour cream. The cases are full of smoked fish, dozens of kinds of kolbasa, and dairy products, and sweet, milky chocolates and cookies line the shelves. $-$$