Step 1In a food processor, grind the shallots, anchovy, olives and walnut pieces to a coarse paste.
Step 2Add the butter and puree until thoroughly mixed. With the machine running, slowly add the olive oil. The paste should become fairly smooth and creamy but still a little chunky.
Step 3Add the lemon juice and Cognac and pulse to mix in. To serve, spread a heaping teaspoon of tapenade on each slice of lightly toasted baguette.