Spinach and Artichoke Baked Eggs

Name: Spinach and Artichoke Baked Eggs
Ingredients: 1 tbsp. olive oil; 1 small onion, chopped; 1 10-ounce package frozen chopped spinach, thawed and squeezed dry; 1 12-ounce jar marinated artichoke hearts, drained and chopped; 2 garlic cloves, finely chopped; 1 tsp. teaspoon kosher salt; 3/4 tsp. black pepper; 2 c. whole milk; 2 oz. cream cheese, cut into pieces; 2 tbsp. grated parmesan cheese; 1 1/2 c. shredded mozzarella cheese; Hot sauce, to taste; 8 large eggs, at room temperature; Crusty bread, for serving