Heat the oil to 340° Fahrenheit in a large pot big enough to contain the oil and the ingredients. Fry the sliced potatoes, separating the slices as you add them to the pot. Be careful as the oil may splatter. Stir with a slotted spoon so the chips stay separate. Remove when they turn golden brown and place on a plate lined with a paper towel. Season with salt immediately.
For the batter, zest and squeeze the juice from one lemon into a bowl with the all-purpose flour. Add the cold sparkling water, black pepper, and sesame seed and mix thoroughly.
Fry battered fish for approximately 3 minutes or until golden brown. Remove and place on a plate lined with a paper towel. Season with salt immediately.
For the dipping sauce, heat a large pot of boiling, salted water. Blanch the zucchini until al dente, remove and shock in an ice bath. Reserve the blanched and cooled zucchini.Blend the zucchini with garlic, yogurt, tarragon, cilantro, and chives.
Serve the fried fish and potatoes with the green dipping sauce