Turn on broiler to medium setting and set oven rack to the top 1/3 setting.
Heat a large frypan over medium-low heat and add olive oil & garlic and sauté for a minute or so, stirring so that the garlic does not brown.
Add chopped spinach, salt & chili pepper and cook until the spinach is wilted, tossing lightly with tongs.
Turn the heat up to medium & add drained artichoke hearts, cooking for another 2-3 minutes, stirring occasionally.
Add cream cheese, mozzarella, & sour cream and continue to cook until the cheeses melt and everything starts bubbling.
Transfer dip to an ovenproof dish and place under the broiler for about 5 minutes, or until the top browns. Eat hot from the oven or room temperature.