Start by spatchcocking the chicken, you can find a guide on how to do it here. If you don't want to spatchcock the chicken then you can just cook the chicken whole and adjust the cooking times accordingly. Preheat the oven to 200°C. Rub the chicken all over with the lime juice, mint leaves and olive oil and leave to sit for 15 minutes.
Place the chicken in the oven and cook for 40-45 minutes (depending on size of the chicken). Remove from the oven and use a meat thermometer to make sure it's cooked through.
While the chicken rests melt the butter in a small saucepan over a low heat. Add the garlic clove, stir and remove from the heat. Break the baguette in half and split open. Brush the inside of the baguette with garlic butter and top with some rocket. Shred some of the chicken and stuff the baguette halves. Serve.