To make this dip, start by heating a skillet, on the stove, over medium-high heat and add in the oil.
While the pan is heating, dice the onion. Then, add it to the hot pan and cook it for 2-3 minutes.
Then, mash the garlic and add it to the pan with the onion, sautéing it for another 2-3 minutes.
Add in the artichoke hearts and lemon zest, cooking them for another 2 minutes, followed by the spinach and seasonings.
Once the spinach has wilted, mix in the cream cheese and yogurt.
Mix to coat everything well, then add in the grated parmesan cheese.
Remove the dip from the heat, then top with an even layer of mozzarella cheese.
Then, turn the oven on to the broil setting and place the pan on the middle or lower rack of the oven.
Allow the dip to cook for 3-4 minutes, until the top gets golden and browned. Be sure to keep a close eye on it, so that the cheese doesn't burn!
Once it's done, remove it from the oven and allow it to cool slightly. Then, serve and enjoy!