Form beef into four 4-ounce rounds, about 1-inch thick. Place in the center of four cold plates. Using the back of a spoon, create an indentation in the center of each round; place egg yolks into indentations.

Cut lemons to create 20 round slices; surround beef with slices. Atop each lemon slice, spoon chopped egg, onion, parsley, capers and anchovy. Serve immediately, letting guests mix tartare ingredients, and season with salt, pepper and Dijon, as desired.

Note: We suggest taking caution when eating raw meat and raw or lightly-cooked eggs, due to the slight risk of food-borne illness. To reduce risk, use only fresh, properly refrigerated, clean grade A or AA eggs with intact shells; avoid contact between yolks or whites and the shell. Use only very fresh, properly refrigerated meat from a reliable market.