“Nose-to-tail” cooking has become a white-hot fad among today’s progressive chefs, who are as proud of their reverence for animal carcasses as they are of their Zagat ratings. But invariably, the commitment to using every last bit of an animal has been limited to pigs. Where’s the guy who is going to use every bit of a 1,200-pound steer? According to Ron Silver of Bubby’s, he is that man. Silver is buying local grass-fed steers from Slope Farms in Meredith, a farm founded by a former Park Slope doctor, Ken Jaffe, who named the place after his old neighborhood. Jaffe raises the animals naturally, and Silver has committed Bubby’s to using every last bit of beef from them. (Slope Farm also supplies the Park Slope Food Co-op.) There’s steak, yes, but also steak and kidney pie, oxtail soup, roasted marrowbones, and chicken fried tri-tip steaks. (And here we always thought of Bubby’s as a place to get biscuits.) The restaurant has even started a “Bubby’s Beef Blog,” Silver says. “If anyone else wants to do whole steer, we can help them. A lot of great things can be done, and it’s a sustainable way to think about one’s meat.” Bubby’s seems determined to become a true meat mecca: Silver also tells us that, come fall, those steer burgers will be sold 24 hours a day.