Heat 1 tablespoon olive oil and the butter in a skillet over medium heat, when butter melts add bread crumbs, onions and lemon zest. Toast the bread crumbs until golden, transfer to a bowl and return pan to heat. Add remaining 2 tablespoons olive oil to the pan and then add the escarole. Turn escarole in oil to wilt, then season with salt, pepper and nutmeg. Add the stock and honey and simmer over low heat 2 to 3 minutes to mellow greens a bit. Squeeze the juice of 1/2 lemon over greens, top with the bread crumb mixture and serve.