Melt a generous amount of butter in a saute pan over medium-low heat. Arrange trimmed and halved endives cut side down in a snug single layer, sprinkle with lemon juice, season with salt and pepper, and add water to come a third of the way up their sides. Cover and simmer until tender. Remove the lid, raise the heat, and cook until any remaining liquid evaporates and the endives brown. Flip and brown the other side. Serve sprinkled with sliced chives.