Place the potatoes in a baking pan and drizzle with olive oil and 2 tablespoons water. Season with salt and pepper. Cover with foil and roast until tender, 40 to 50 minutes. Let them cool. Remove from the oven and cut into rough 1 ½-inch chunks.
In the meantime, in a bowl or a blender, mix or whisk together the sour cream, avocado, garlic and lime juice. Season with salt. Set aside.
In the meantime, toss the jalapeno slices in flour, salt and pepper.
Heat the oil in a deep heavy saucepan. Fry the potatoes until they are almost done, golden and crispy. Add the jalapenos for the last one minute until the jalapenos and jalapenos are golden brown and crispy.
Remove and drain well. Toss with the Spice Mix. Place in a bowl, sprinkle with maldon salt and garnish with cilantro sprigs and lemon wedges. Serve with a bowl of Avocado Crema for dipping.