Making pregnancy look ridiculously easy, new mom Vanessa Lachey strided out of Mastros Steakhouse in Beverly Hills, Calif., Monday night. The televisionpersonality wore a silky dress and fitted blazer that showed off her already-slim frame -- just four weeks after giving birth to her first child. Vanessa, 31, and husband Nick Lachey, 38, welcomed son Camden John on Sept. 12."We are incredibly proud to announce the birth of ourbeautiful baby boy, Camden John Lachey. Born today at 6:54 p.m., he came into this world at 8 pounds, 9 ounces and 21 inches. Love has truly been redefined for both of us," the couple announced in a statement at the time. Earlier this month, Vanessa shared a first glimpse of baby Camden in a photo posted to her Twitter page. "[Nick] and I are honored and humbled to introduce you to the new Love of our lives, Camden John Lachey," she wrote.