Melt the coconut oil in a well-seasoned cast-iron pan over medium-high heat. Add all of the Brussels cut-side down and pan roast for about 5 minutes, until slightly golden brown. Salt the Brussels with about 1/2 teaspoon, more or less taste if needed. Carefully add the water to the pan (it will sizzle) and cover the pan tightly. Allow the Brussels to steam about 4-5 minutes to finish cooking. Serve warm or room temperature. These also keep well in the refrigerator for up to 3 days for healthy snacking.