In a food processor, combine the chopped artichokes, anchovies, garlic, and the prepared onion. Blend until you achieve a creamy consistency. For an even smoother texture, consider using an immersion blender.
Incorporate the mayonnaise, lemon juice, and a touch of olive oil into the mixture by pulsing a few times until thoroughly combined.
Season with salt and freshly ground pepper to your liking. Transfer to a jar and refrigerate. This spread retains its freshness for up to 3 days.