Preheat the broiler. Carve off all of the bottom and most of the top and side crusts from your bread (you can reserve these to use as croutons for soup or another salad). Tear bread into irregular 2- to 3-inch chunks—you should get about 4 cups.
Toss them with a tablespoon or two of olive oil, lightly coating them, and broil very briefly, just to lightly color the edges. If you’d like to toast the pine nuts (recommended) you can put them on your broiler tray as well, but watch them very carefully because they cook quickly!
Combine about 1/4 cup of the olive oil with the Champagne or white wine vinegar and salt and pepper to taste. Toss about 1/4 cup of this tart vinaigrette with the torn toasted bread in a wide salad bowl; the bread will be unevenly dressed. Taste one of the more saturated pieces. If it is bland, add a little salt and pepper and toss again.
Heat a spoonful of the olive oil in a small skillet, add the garlic and scallions, and cook over medium-low heat, stirring constantly, until softened. Don’t let them color. Scrape into the bread and fold to combine. Drain the plumped currants and fold them in, along with the pine nuts, if they were not already mixed with the bread scraps from the broiling step. Dribble the chicken stock or lightly salted water over the salad and fold again.
Taste a few pieces of bread—a fairly saturated one and a dryish one. If it is bland, add salt, pepper, and/or a few drops of vinegar, then toss well. When the chicken comes out of the oven, drizzle the bread with a spoonful or two more of chicken pan juices and toss. Add the greens, a drizzle of vinaigrette, and fold well. Taste again.
Pile the bread salad on the serving dish. Carve the roast chicken and plunk the pieces on top of the salad, using more pan juices to moisten the bread as needed.
I have a thing for most foods topped with a fried egg, a strange disdain for overly soupy tomato sauce, and I can never make it home without ripping off the end of a newly-bought baguette. I like spoons very much.