For the pickled jalapenos: In a small saucepan, combine the lime juice, vinegar, sugar, salt, and jalapenos. Bring to a simmer over medium-high heat, stirring occasionally until the sugar dissolves, about 2 minutes.Transfer to heat proof container and cover with plastic wrap and let cool for about 20 minutes. Transfer to the refrigerator for at least 15 minutes and up to 2 days.
For the carnitas: Cut the pork shoulder into 1 1/2- to 2-inch pieces and put them in a large Dutch oven or heavy pot. Add the lime juice, orange juice, garlic, chili powder, coriander, cumin, and salt. Add just enough water to cover the pork and bring the mixture to a boil. Reduce the heat to medium-low, cover, and cook for 30 minutes. Remove the lid and continue cooking at a gentle simmer for at least 1 1/2 hours but no longer than 2 hours, stirring occasionally and taking care that there is still liquid in the pot.
Increase the heat to medium-high and cook, stirring, until all of the liquid has been absorbed or evaporated, about 10 minutes. Continue cooking, carefully turning the pork pieces, until they develop brown, crispy edges, about 5 minutes.
For the tacos: Assemble the tacos using the warm tortillas and the carnitas. Top with the pineapple, cilantro, cabbage, cheese, Pickled Jalapenos and a squeeze of lime juice. Season with salt. Reserve the remaining pork for another use. Serve alongside guacamole and pico de gallo, if desired.
Sponsor recipe courtesy of Kelsey Nixon for Lipton