Remove and discard the fat just inside the body cavities of the chicken. Remove the package of giblets, and set aside for another use. Rinse the chicken inside and out, under cold running water, then drain and blot dry, inside and out, with a paper towel.
Oil chicken all over with the olive oil and sprinkle the Chermoula spice over the outside of the chicken. Cover and refrigerate the chicken while the BBQ is heating. Set the kettle BBQ for indirect grilling, place a drip tray in the center.
If using a gas grill turn to hot first to heat and then turn down to medium to cook. Pop the tab on the beer can and use a can opener to make 4 more wholes around the edge of the can to allow beer to steam the chicken. Holding the chicken upright, with the opening of the body cavity down, insert the beer can into the cavity.
When ready to cook, oil the grill grate, stand the chicken up in the center of the hot grate over the drip tray. Spread out the legs to form a sort of tripod, to support the chicken.
Cover the grill and cook the chicken until fall of the bone tender about 2 hours. If using charcoal, add 10 to 12 fresh coals per side after 1 hour. Using tongs lift the bird on to a cutting board, holding a metal spatula underneath the beer can for support.
Careful not to spill hot beer on yourself. Let stand for 5 minutes before carving. Toss the beer can out with the carcass
Method for Mango sauce
Place mango chutney in food processor and process until smooth in texture. Place in bowl with cream and mix until combined. Put into saucepan and slowly heat (do not allow to boil).
Heat until warm and pour over the top of the chicken and serve.. CHEFS TIPS: This is the most succulent chicken you will ever taste. You will go back to this recipe many times. It stays just as moist the next day. ( If there is any left, that is).