First, make your salsa. Combine all ingredients in a medium bowl. Refrigerate until ready to use.
Now, latkes time. Start by shredding your potatoes with a grater into a bowl of ice water. Let sit for 10 minutes. Remove potatoes, squeezing out the moisture into the water. Dry potatoes very well with towels. Let water sit 10 minutes for starch to accumulate on the bottom. Carefully drain water, reserving the white starch on the bottom.
Place potatoes in a large bowl, dry again very well. Then add in the spinach, onion, garlic, egg, flour and salt and reserved starch and combine.
Meanwhile, heat up vegetable oil in a large saute pan. Scoop two tablespoon dollops of the potato mixture and flatten lightly and fry until golden brown, about 3 minutes. Then flip and fry the other side. Season immediately with salt and drain on a rack over paper towels. Repeat with remaining latkes.
Serve latkes immediately with sour cream, lucky salsa and green onions.