- For the masa mixture, puree the corn, onion and stock in a food processor. Transfer mixture to a mixing bowl and cut in the butter and shortening. Using your fingers, mix in the cornmeal, sugar, salt and ground black pepper. Set aside.
- For the pumpkin filling, in a separate mixing bowl, combine the pumpkin puree, liquid honey, ground cinnamon, ground nutmeg and ground cumin. Add the pumpkin filling to the masa mixture, marbling it through the masa.
- For the orange-ginger butter, place butter, orange zest, nutmeg, grated ginger, salt and ground black pepper into a food processor and blend until evenly combined. Cut a piece of foil approximately 25 centimeters by 20 centimeters). Spread the butter in a block about 15 centimeters long and five centimeters thick in the middle of the foil. Roll up. Refrigerate for at least 30 minutes.
- To make the tamales, pick out 20 of the best cornhusks.
- Tear the remaining husks into thin 1.5 centimeter strips; these will be used for tying.
- Lay two husks flat on a work surface with the tapered ends facing out and broad bases overlapping by 7.5 centimeters.
- Place about 1/3 cup (80 milliliters) of the masa mixture mixed with the pumpkin filling in the centre. Bring the long sides up over the filling, slightly overlapping, and pat down to close. Tie each end of the bundle with a strip of the cornhusk, pushing the filling towards the middle as you tie. Trim the ends. Repeat until all corn husks are used up.
- Preheat one side of barbecue to 220F (105C).
- Place a drip pan under the burners that are off.
- Place the tamales over the grates with the drip pan below.
- Allow the tamales to slow cook with lid down for 35-40 minutes.
- Remove from barbecue.
- To serve, using a knife, make a long cut lengthwise, place a slice of the butter on top of the hot filling.
Note: Cooking times and temperatures will vary depending on the size and type of your barbecue.