Preheat the oven to 350° F. Spread the rough sides of the pita evenly with the goat cheese, season them with salt and pepper, and sprinkle the walnuts evenly over the cheese, pressing them in gently. Cut the pita into 1-inch pieces and bake the croutons on a baking sheet in the middle of the oven for 15 to 25 minutes, or until they are golden.