If we're calling a spade a spade, this is like a Niçoise Salad in a sandwich but people tend to get really offended if you say that. There are countless variations, but this {Pan Bagnat} Classic Nice-Style Sandwich recipe version is my favorite.
Make The Anchovy Dressing: Whisk together the anchovy, garlic, vinegar, salt and pepper in a small bowl. While whisking constantly, slowly drizzle in oil. Add a pinch of salt and pepper, taste, and adjust as desired. If using a French roll, pull out some soft interior crumb to form a cavity.
Assemble The Sandwich: Spread half of the artichokes and tuna on the bottom. Top with tomato and olives, then radishes, basil, and egg slices. Top with vinaigrette. Cover with second bread half and firmly press sandwich together. Wrap sandwich tightly in foil.
Put sandwich under a weight such as a cast iron pan topped with a filled kettle. Weight sandwich for 7 to 10 to 15 minutes, then flip and weight it for another 10 to 15 minutes. Unwrap, slice and serve immediately, or keep it wrapped for up to 12 hours before serving.