Peel the pineapple and cut into 2cm slices. Take two slices and chop. Set aside.
Grill or roast the tomato on a ridged griddle pan or under the grill till slightly charred. Remove from heat. Once cool enough to handle, peel and remove the seeds.
Combine the dried chillies in a small pan of boiling water. Boil for 5 minutes, till softened, then drain.
In a blender or food processor, combine the reserved chopped pineapple, tomato, softened chillies, chillies in adobo sauce, onion, garlic, orange juice, vinegar, cloves, cumin, oregano and salt. Blend till smooth.
Place the pork in a glass or ceramic dish. Pour the marinade over the pork, ensuring that all sides of the pork are covered in the marinade. Cover with cling film and place in the fridge to marinate for at least 4 hours, or overnight.
Preheat a ridged griddle pan to medium-high heat. Cook the pineapple slices for 10 minutes, turning once, till slightly blackened and soft.
Preheat another ridged griddle pan to medium-high heat. Place the marinated pork on the hot pan, and cook 4 to 5 minutes, turning once halfway through.
Remove the pork from the pan. Roughly chop the pork into small pieces against the grain of the meat. Chop the pineapple into small pieces, discarding the core.
Serve the pork and pineapple with warm corn tortillas and a variety of accompaniments, including coriander, onion, tomatillo salsa and lemon or lime wedges.
The chillies called for in this recipe are mild in heat. Try looking at speciality shops or online, such as Mexgrocer.co.uk. In a pinch, use a mix of dried red chillies and mild dried red Spanish peppers.