I picked up a package of frozen beef marrow bones for next to nothing at the market, envisioning them roasted and the marrow spread like butter on good ciabatta toast with maron salt flakes and a little parsley or gremolata. That's the idea anyway - how do I get there? All the recipes I see call for boiling them or splitting the bone open (!) to get at the marrow. Can't I just roast them at high heat and go at it with a marrow spoon?