For the chicken: Using kitchen shears, remove the backbone of the chicken and set aside in the refrigerator for another use (such as Smoked Chicken Minestrone). Cut the chicken in half, straight through the breastbone. By separating the chicken into two pieces it will ensure that the chicken gets smoked more thoroughly. Sprinkle the chicken pieces with salt, pepper, the granulated garlic and smoked paprika.
Place 1 deep aluminum roasting pan over the stove top. Line with aluminum foil. Add the soaked wood chips to a large piece of foil, and then fold in the sides to make a pouch. Punch holes in the top of the pouch, set it directly over a gas burner and turn on high. Leave for 2 to 3 minutes, watching carefully. Once it begins to smoke, using tongs, transfer the pouch to the bottom of the lined roasting pan. Set a wire rack over the chips in the lined roasting pan and position it so the wood chips are directly over the burner and continue to smoke. Place the chicken pieces bone-side down on the rack. Cover tightly with aluminum foil to seal in the smoke. Put the roasting pan into the oven and smoke until the internal temperature reaches 165 degrees F on an instant-read thermometer, 45 to 60 minutes. Remove and cool. Shred the smoked chicken breast and set aside 1 1/2 cups for the cannelloni (reserve the rest for another use). Increase the oven to 375 degrees F.
While the chicken is smoking, make the creamy roasted red pepper sauce: Bring the oil to medium heat in a large saucepot. Sweat the onions until translucent, about 3 minutes. Add the garlic and sweat until fragrant, about a minute. Stir in the peppers and tomatoes. Simmer for 5 minutes. Working in 2 cup batches, process the sauce on high in a blender until smooth. Return the sauce to the pot, reduce the heat to low and whisk in the cream. Remove from the heat and stir in the lemon juice. Season with salt and pepper. If making ahead, cool before refrigerating for up to a week.
For the cannelloni: In a medium mixing bowl, combine the ricotta, cream cheese, 1 cup of the Parmesan, the egg and nutmeg with a wooden spoon. Fold in the reserved shredded chicken, spinach, tomatoes and some salt and pepper. Spoon the filling into a medium pastry bag fitted with a large open tip. Spread 1/2 cup of the creamy roasted red pepper sauce evenly on the bottom of a 9- by 13-inch gratin dish. Pipe about 2 1/2 tablespoons of the filling into the cannelloni shells and place them into the gratin dish. Spoon the remaining sauce over the cannelloni. Sprinkle with the panko and remaining Parmesan. Cover and bake until the filling is cooked through, about 30 minutes. Bake uncovered until the top is golden and bubbling, an additional 5 to 7 minutes. Remove and cool on a resting rack. Garnish with Parmesan and serve.