Preheat the oven to 400 degrees F. Remove the chicken from the refrigerator to come up to room temperature. Line a heavy-duty rimmed baking sheet with foil.
Place the chicken on the baking sheet, and place the lemon halves in the cavity. Sprinkle the skin with salt and pepper and drizzle lightly with olive oil. Roast the chicken until a thermometer inserted into the thickest part of its thigh reads 165 degrees F, 1 hour 15 minutes. Remove from the oven and let rest for 30 minutes.
Whisk together the mayonnaise, yogurt, curry powder, lemon juice, hot pepper jelly, Dijon mustard and green onions in a medium bowl and season with salt and pepper.
Shred the cooled chicken and discard the skin. Chop into chunks. Fold the chicken, smoked almonds and cranberries into the mayonnaise mixture.
Add a big scoop of chicken salad to a slice of bread and top with baby arugula and a second bread slice. Slice in half and serve.