For the croutons, cut the baguette into bite-sized cubes. Heat 2 tablespoons of olive oil in a large, nonstick skillet and toast the bread cubes until golden brown. Drain on absorbent paper.
For the salad, rinse the tomatoes and the cucumber. Cut the bell peppers into quarters and rinse. Chop all the prepared vegetables into pieces. Trim and rinse the celery and cut into slices.
For the dressing, heat the remaining olive oil in a small pan and toast the pine nuts in it. Peel the garlic and crush into the pan. Stir in the vinegar and season with salt and pepper.
Mix the vegetables with the pine nut dressing and fold in the croutons. Serve garnished with basil leaves.