Make the pickles: Combine the water, vinegar, sugar and salt in a medium bowl and stir until the sugar and salt dissolve; pour over the cauliflower and cucumber in another medium bowl and let sit for at least 15 minutes.
Meanwhile, prepare the salad: Heat 1 inch of oil to 400 degrees F in a deep skillet. Add the chickpeas and cook, flipping occasionally, until deep golden brown and crisp, about 5 minutes. Transfer the chickpeas to paper towels with a slotted spoon to drain, then sprinkle with salt and pepper.
Combine the fennel, all of the herbs and jalapeno in a large bowl. Drain the cauliflower and cucumber pickles and add to the bowl. Add the fried chickpeas, tahini and yogurt. Toss to combine and serve!