Disclaimer: I own neither Harry Potter nor any of its characters.
Warning: Contains very strange pudding ingredients.
Meanwhile, Rabastan was mixing his signature cake mix (it's best not to inquire on what was in the cake mix) with plums, cheap beer, maraschino cherries (according to him; judging by the smell, they were pickled), wheat flour, a cup of apparently rotten crabapples, and a currant. "We're out of almonds. Go buy as many as possible, Narcissa. The pudding won't work without them," said Rabastan.
"No. Do I look like a house-elf to you?" replied Narcissa. "I'll just go promenade around the garden while you cook, shall I?" With that, she left, leaving Rabastan grumbling.
"Well, the pudding will have to deviate from the recipe," said Rabastan. Seeing a rat scurrying past the stove, he scooped it up, stuck it in the pudding, and started stirring. Only after the rat had drowned in pudding batter did he notice the silver-looking front foot. He shrugged and continued stirring the batter. After a few minutes, he poured the batter into a cauldron that had held a potion a few hours earlier. He added butter, suet (the kind one buys for birdfeeders, judging by the package), a chopped pickle, and a few unfortunate ants.
Thirty seconds after the ants had gone in, Voldemort opened the door. "Where is Narcissa, and what are you putting in that pudding?" he demanded.
"Narcissa is promenading around the garden, my lord," replied Rabastan.
"And what is going into that pudding?"
"Ale, apples, plums, currant, cake mix, cherries, flour, butter, and suet. Anything you object to?"
"What is that, then?" Voldemort pointed to a protruding tail.
"Oh, a rat must have fallen in. I'll take it out." With that, Voldemort left. Rabastan continued stirring the pudding. After a few minutes, he poured vegetable oil onto a frying pan, turned the heat on, and poured the pudding into the pan. He left the room.
About an hour later, Rabastan returned to find the pudding thoroughly burnt. He put it in the icebox soaking in the rest of the cheap beer.