Preheat the oven to 375°F (190°C).
Slice the baguette into 1/2-inch thick slices and arrange them on a baking sheet.
Lightly brush the baguette slices with 1 tablespoon of olive oil and toast in the oven for 7–10 minutes until golden and crisp.
While the bread toasts, combine the walnuts, green olives, anchovy fillets, and garlic clove in a food processor.
Pulse the mixture until coarsely chopped but not pureed, scraping down the sides as needed.
Slowly drizzle in the remaining 2 tablespoons of olive oil while pulsing until the mixture forms a chunky spread.
Season the olive-walnut spread with a little black pepper to taste (skip salt as anchovies and olives are salty).
Spread a generous layer of the olive and walnut mixture onto each toasted baguette slice.
Arrange on a serving platter and serve immediately, optionally garnished with fresh parsley or lemon zest for brightness.