Combine the Parmesan, cream cheese, mayonnaise, sour cream, lemon juice, lemon zest, artichokes, garlic and chiles in a large mixing bowl. Mix completely and spread evenly in a shallow 1-quart baking dish. Top with the shredded Cheddar.
Bake until bubbling and the top starts to brown in spots, 25 to 30 minutes. Serve warm with sliced baguette.