Prepare the sauce by combining the ¾ cup Vegenaise, garlic, lemon juice, agave, ½ teaspoon salt, ¼ teaspoon pepper and minced chives in a mixing bowl. Grate the peeled cucumber into a paper towel and squeeze out all the juice. Stir into the sauce mixture, place in a serving dish, cover and refrigerate until serving time. Can be made a day or two ahead.
For the fish, preheat the oven to 400 degrees and line a baking sheet with parchment paper or a silicone baking mat.
Arrange the fish filets on the prepared baking sheet and sprinkle with a small pinch of salt and a large pinch of pepper then brush each fillet with ½ teaspoon of Vegenaise. Top the fish filets with the crushed potato chips, gently pressing them down. Bake for 10 minutes or until the fish flakes easily with a fork.