Cafeteria 15L–a reboot of Mason’s Restaurant at the corner of 15th and L–opens today with a menu that emphasizes affordable comfort foods like meat loaf and mashed potatoes and macaroni and cheese. According to owner Mason Wong, most entrees will be priced in the teens. The most expensive thing on the menu: a 14-ounce cut of prime rib for $26. Heading up the kitchen is Jonathan Kerksieck, formerly with Masque Ristorante and Grange. Over the weekend, he and his crew were busy cooking for “friends and family” events designed to get the kinks out before today’s opening. In addition to comfort foods, the menu includes some wild cards, such as a Hangtown Fry (fried oysters and poached eggs) and a smoked trout sandwich.