Fill a small bowl with cool water and a splash of vinegar, clean the lemons. TIP: The vinegar helps clean fruits and veggies, and leaves no after-taste. Cut each lemon lengthwise into 8 pieces. Place on the large sheet pan.
Fill a small bowl with cool water and a splash of vinegar, clean the potatoes. Cut small potatoes in half. Place on the large sheet pan.
Next, slice the baguette bread loaf into 1" pieces and place those onto the sheet pan. Drizzle the oil, salt, and pepper and toss lemons, potatoes, and bread cubes well to combine on the sheet pan. You can also do this in a very large bowl, but that is one more thing to clean. In a small bowl, mix smoked paprika (not hot paprika) and lemon pepper. Next, cut the chicken breasts into 1” cubes, and toss the chicken cubes in the paprika and lemon pepper mix.
Place chicken pieces on top of lemons, bread, and potatoes. Bake at 400 degrees 25 minutes, then drizzle a little more olive oil and toss again using tongs. Finish baking at 400 degrees for 25 more minutes until the bread is toasted, potatoes are tender, and the chicken is lightly browned and baked with the juices running clear and an internal temperature of 165 degrees.