Gregory Sonnenburg, who for the past 10 months has functioned as the sommelier and cellar master at Nana, has been bumped up to manager. Sonnenburg previously functioned as assistant wine steward at the Del Frisco's in Fort Worth, as well as assistant general manager at Houston's in Dallas. Filling Sonnenburg's sommelier void will be Fabian Hernandez, who did stints at Capital Grille and Palamino Euro-Bistro as well as Steel Restaurant & Lounge, where he was cellar manager during Nana's refurbishment, and his work helped land Steel a Best of Award of Excellence from the Wine Spectator.