To make the croutons, preheat the oven to 400° F.
Arrange the slices of bread on a baking sheet. Brush one side of each with the olive oil. Sprinkle with the salt and pepper. Bake until golden brown, about 15 minutes. Remove from the oven and let cool a bit. Spread the croutons with the roasted garlic purée.
While the croutons are baking, prepare the lettuce: Tear the larger leaves into bite-size pieces, and leave the smaller, tender leaves whole. Toss in a large salad bowl with the desired amount of dressing.
Divide the greens among four salad plates and serve with the croutons on the side.