Preheat your oven to 400 F. Peel off the loose outer layers of the head of garlic. Slice off about 1/4 inch off the top of the garlic head. Drizzle a couple teaspoons of olive oil over and cover the bulb with aluminum foil. Bake for 30 minutes. Let cool, and use 2-3 of the roasted cloves for the dip.
Place 2-3 cloves of roasted garlic, artichoke hearts, spinach, sour cream, onion, garlic, Parmesan, milk, feta, vinegar, lemon juice, salt and pepper, and red pepper flakes into a slow cooker. Stir until well combined. Top with cream cheese.
Cover and cook on low heat for 2 hours.
Uncover and stir until cream cheese is well combined.