In a blender, puree the green garlic sauce ingredients with 1/4 cup water.
For the tacos, heat a large skillet or griddle over medium-high. In a medium bowl, toss the shrimp, cumin, chili powder and granulated onion; season with salt and pepper. Add the oil to the skillet, one turn of the pan. Cook the shrimp, turning occasionally, until just opaque in the centers and browned at the edges, about 2 minutes. Add a few dashes cayenne sauce to the shrimp and douse with the lime juice.
In a large, dry skillet over high heat or directly over the open flame on a gas stovetop, cook the tortillas, turning occasionally, until charred in spots, about 2 minutes.
Fill the tortillas with the cabbage, avocado, shrimp, green garlic sauce, cheese, radishes and pickled jalapeño slices.
One Quick Hack for Dicing Avocados