Drain the soaked almonds, transfer to a blender and add half a cup of water, process for a few minutes until the almonds are ground.
Place a nut milk bag on a vessel and pour the almond mixture into the bag. Squeeze the bag as hard as possible. Transfer the pulp left in the bag to a bowl.
Add almond butter, olive oil, lemon juice, apple cider vinegar, garlic powder, and salt.
Knead the mixture well, taste and adjust seasoning if necessary.
Shape the mixture into a square about 1 cm thick (3/4 inch and 5-7 cm long (2-3 inch). Wrap in cling film and refrigerate for at least an hour.
Remove from the refrigerator and brush with olive oil on all sides.
Heat a griddle pan and sear the feta on both sides. Set aside.