Combine the shredded potatoes, grated onion, feta cheese, spinach, flour, salt and pepper in a large bowl.
Whisk egg in a separate bowl and combine with the potato mixture.
Heat a large skillet with ⅓“ oil over medium-low heat.
Fry the latkes by measuring out a ¼ cup of mix and squeezing out any the liquid and placing them in the hot oil.
Flatten out a bit like a pancake.
Fry for 2 ½ – 3 minutes per side in batches making sure not to crowd the pan. (Add more oil if needed between batches.)
Remove the latkes from the oil and transfer to the cooling rack.
Sprinkle with Maldon or flaky sea salt.
Serve with ½ cup sour cream mixed with 1 tsp dill and ¼ cup crumbled feta. See Danielle’s original recipe here https://iwillnoteatoysters.com/spanakopita-latkes/