►CILANTRO BUTTERMILK: Place cilantro and buttermilk in a blender and purée until smooth. Transfer to a bowl and whisk in the sour cream and salt. Any leftover cilantro buttermilk can be stored in the refrigerator for up to five days.
►TO GRILL: Preheat grill to medium-high heat
►Toss zucchini halves with the olive oil, salt, cumin, and coriander. Place zucchini cut side down on grill grates and grill until charred, about 4 to 5 minutes. Flip zucchini over and cook for an additional minute. Remove from heat and let cool to room temperature before cutting into bite size pieces.
►To serve, spoon a generous amount of cilantro buttermilk onto a serving platter. Arrange the zucchini on the platter and top with queso fresco, pine nuts, and pea tendrils.