Heads up, pancake purists: It’s worth the pilgrimage to Rio Ranch [9999 Westheimer, Westchase Hilton, (713)952-5000] for a short stack of tender buttermilk pancakes, gems of the Ranch Hand breakfast ($11.95 buffet or $4.95 $egrave; la carte). So scrumptious, these made-to-order babies don’t need to boast a Texas-size girth to…