Rub: Combine the rub ingredients, in a small bowl and massage it into the pork shoulder until well coated. Set aside while you make BBQ sauce. You could do this a day ahead and keep refrigerated until ready to use.

BBQ sauce: In a large saucepan, warm the oil, over low heat, until hot and shimmering. Add the cumin and fennel; they should splutter upon contact - be careful! Once the spluttering subsides, add the onions, ginger and serrano and a little salt, to taste. Saute until they soften but don't let them get any color. Add the rest of the sauce ingredients. Simmer about 5 minutes. Taste and season.

Add the pork shoulder to the saucepan, coating it with the sauce. Cover, and gently simmer until the pork falls apart easily, stirring and turning often, about 3 hours.

Remove the pork from the saucepan and shred it using 2 forks. Return it to the sauce and stir to coat with the sauce. Put a generous spoonful of the pork inside a brioche bun, top with a few slices of pickle and serve. Cook's Note: prepare to have your loved one swoon over you!