Poached stock vegetables are beautiful doused in flavoured brown butter and warm yoghurt
Stock vegetables are an accepted form of waste for most chefs and home cooks. Yes, stock is a great way to use up less desirable or inedible parts of fresh vegetables – carrot tops, onion skins, pea pods, celery butts, corn husks, etc – but, to taste nice, most stocks will likely also need to contain whole onions, carrots, celery, leeks and other prime vegetables. Yes, some of their flavour and nutrients will leach out into the cooking liquid, but the vegetables will still be nutritious, tender and perfectly fine to eat. To reduce waste, whenever I make stock now, I choose the vegetables I use carefully and serve them alongside the meal, as in many traditional dishes from cocido, a Spanish chickpea and meat broth, to bollito misto, the classic northern Italian stew.
To make meat stock, simmer meat bones with any inedible vegetable scraps, peppercorns, bay leaves and woody herbs for as long as they need (one to three hours, depending on the meat), then strain the stock, return it to the heat, add your prime vegetables (halved onions, leeks, halved carrots, celery sticks, etc), bring back to a boil and simmer for 30 minutes. By this point, the vegetables will have imparted enough of their flavour and be cooked to perfect tenderness.