In a small bowl mix together the mustard, honey, Worcestershire sauce and paprika. Put one chicken breast in a freezer / sandwich bag and using a mallet or heavy object, firmly bash until it is about 1cm thick. Repeat with the second chicken breast.
Put half the marinade in with both pieces of chicken and mix until the chicken is covered. Leave in the fridge or cool box for about 1 hour.
Pre-heat your BBQ over medium heat for 2-3 minutes with the Paella Pan in place. Mix the crème fraîche with the remaining marinade and keep to one side.
Fry the chicken in a little oil for 3-4 minutes on each side or until cooked through. Pour the reserved cream and marinade mix into the pan and turn the heat up, let the sauce bubble up and once it starts to thicken turn off the heat and serve immediately.