Add some olive oil to a skillet, when hot, add the onions, saute in medium heat until the onions are golden. Reserve.
Chop the spinach, add it to a bowl along with the remainder of the ingredients for the spinach balls.
Mix all very well then form small size balls.
Preheat the oven at 180C (356F).
Place the balls in a baking sheet, cover them with aluminum foil or plastic film, and put them in the fridge for 30 minutes or in the freezer for 15 minutes.
Remove the balls from the fridge or freezer, uncover them, and put them in the oven for 35 to 40 minutes. This time can vary according to your oven.
Meanwhile, add all the ingredients for the dip in a small-sized bowl and mix them until incorporated.