6 ciabatta rolls, or 6 large slices crusty Italian bread
½ cup grated part-skim mozzarella
1. Sprinkle the chicken with salt and pepper. Place the flour on a sheet of waxed paper. Toss the chicken chunks in the flour and coat completely. Preheat the oven to 350 degrees.
2. Warm the oil in a large skillet over medium-high heat. Add the chicken and garlic. Decrease the heat to medium and continue to cook until the chicken begins to brown and the garlic becomes fragrant, 8 to 10 minutes.
3. Add the chicken broth, vinegar, and brown sugar. Bring to a boil. Cover and simmer 10 to 15 minutes, until the chicken is cooked through and no longer pink in the center. Add the puree and cook 2 to 3 minutes more, until the flavors are well blended.
4. Place the bread on a large baking sheet. Top each with a tomato slice. Divide the chicken between the 6 pieces of bread and top with mozzarella. Bake until the cheese is melted and edges of the bread are crisp, 5 to 7 minutes. Serve immediately.
For the Broccoli Puree
Cut broccoli into florets and steam for 6 to 7 minutes. Florets should be tender but still bright green. (If they're an olive green, they're overcooked.) Puree using a food processor or blender for about 2 minutes. May need a few teaspoons of water, for a smooth, creamy texture.