Slice the top crown off the sourdough boule using a long serrated knife and carefully hollow out the soft interior crumb, leaving thick stable walls of about three quarters of an inch all around to hold the saturated fat load without leaking.

Thaw the frozen chopped spinach completely, then transfer it into a double layer of cheesecloth and wring it aggressively over the sink until every drop of green tinted water has been extracted and the spinach feels almost dry to the touch.

In a large mixing bowl, fold together the softened block cream cheese, cultured sour cream, freshly minced garlic, sea salt, and cracked black pepper using a silicone spatula until you achieve a uniform pale creamy base with no visible lumps.

Gently fold the bone dry spinach, chopped artichoke hearts, and three quarters of the hand grated mozzarella and parmesan into the creamy base, taking care not to overmix or apply mechanical shear that could rupture fat globules.

Spoon the cohesive mixture tightly inside the hollowed bread bowl cavity, pressing down to eliminate air pockets, and top generously with the remaining reserved cheese for a golden brown caramelized crust.

Place the assembled bread bowl onto a parchment lined sheet pan or inside a cast iron skillet and bake in a preheated oven at 375 degrees Fahrenheit (190 degrees Celsius) for 20 to 25 minutes, until the internal temperature reaches 165 degrees Fahrenheit (74 degrees Celsius) and the cheese crust bubbles with deep brown caramelized spots.

Rest the baked bread bowl on the counter for approximately three minutes to allow the dairy emulsion to stabilize, then serve immediately surrounded by the reserved torn bread cubes and crisp fresh vegetable dippers.