Preheat your oven to 425°F. Lightly spray a medium baking dish with olive oil.
Heat your oil in a pan on medium. Add the scallion and sauté for 3 minutes. Add the spinach and stir until mostly wilted. Add in the garlic and stir around for 30 seconds. Transfer the mixture to a colander and press out as much liquid as you can with paper towels.
Pat your artichoke pieces with a paper towel until mostly dry.
In a large bowl, combine the spinach, artichokes, dill, cream cheese, mayo, sour cream, HALF of the feta, 2/3 of the shredded mozzarella, Sriracha, salt and pepper to taste. I ended up using my hands to get everything fully incorporated. Transfer the mixture to your baking dish and spread out evenly. Top with the remaining feta and mozzarella and bake for 20-25 minutes. Top should be mostly golden brown.
Serve with warm pita, tortilla chips or crostini bread.
Notes
You can use frozen spinach, just thaw and drain of all liquids.SAVE your leftovers and top your grilled chicken the next day.