Combine the bread flour, active dry yeast, sugar, and salt in a large bowl. Add the lard and warm water, then mix until a shaggy dough forms. Knead for 8–10 minutes until smooth, elastic, and only lightly tacky. The dough should feel soft but not sticky. If it feels dry and tight, add a small splash of water. If it is very sticky, add a little flour. Transfer to a lightly oiled bowl, cover, and let rise until doubled, about 1 hour to 1 hour 15 minutes. Lard rather than butter or oil is the traditional fat here, and it contributes to Cuban bread's specific tender-but-not-rich crumb — a texture that's noticeably less enriched than a brioche-style loaf but more tender than a lean baguette dough.

While the dough rises or earlier in the day, blend the shallots, garlic, orange zest, lime zest, dried oregano, mint, cumin, serrano chilies, olive oil, salt, lime juice, and orange juice until mostly smooth. The marinade should be fragrant, citrusy, and loose enough to coat the pork well. Blending rather than simply mixing the aromatics distributes the citrus zest, herbs, and chilies evenly throughout the liquid, so every part of the pork's surface gets equal exposure to the same concentrated flavour rather than uneven pockets of chopped ingredients.

Trim only any very excessive exterior fat from the pork shoulder. Place the pork in a dish or zip bag and pour over the marinade. Turn thoroughly to coat. Cover and refrigerate for 4–12 hours. Do not skip the marinating time. This is the main flavor base for the whole sandwich. Because this marinade travels with the pork straight into the roasting dish rather than being discarded, the marinating window here is less about a hard tenderising cutoff and more about giving the citrus and herbs enough time to genuinely penetrate the meat's surface before that same liquid becomes the braising base.

Punch down the risen dough and divide it into 2 even pieces. Shape each piece into a tight log about 16 inches / 40cm long, keeping them slender and even. Place on a parchment-lined tray, leaving space between them. Cover lightly and let rise again for 45–60 minutes until puffy. Bake at 220°C / 425°F for 18–22 minutes until golden-brown. The crust should be thin and crisp, not thick and hard. Cool fully. Each 16-inch loaf will later be cut into 2 sandwich portions, giving 4 whole 8-inch sandwiches total. Shaping the dough into a tight, even log rather than a looser or rounder shape is what gives the finished loaf its narrow, elongated profile — a wider or more irregular shape would produce sandwiches that press unevenly and don't match the classic Cubano proportions.

Remove the pork from the refrigerator 30 minutes before roasting. Transfer it with its marinade to a covered Dutch oven or roasting dish. Add 120ml chicken stock around the pork if the liquid level looks too low. Cover and roast at 160°C / 325°F for about 2 hours 30 minutes. Turn the pork once or twice during cooking. Add a little more chicken stock only if the pan starts drying out. Uncover for the last 20–25 minutes so the exterior can deepen in color slightly. The pork should be fully tender but still sliceable, not braised into total collapse. Covering the pork for the bulk of the roast keeps it essentially braising in its own marinade, which is what carries all that citrus and herb flavour directly into the meat over the long cook — the brief uncovered finish at the end is purely for colour, not for any further tenderising.

Let the pork rest for 15–20 minutes. Slice thinly across the grain. If some parts want to shred slightly, that is fine, but the majority should stay in thin juicy slices or soft sliced chunks. Keep a little of the pan juices to moisten the sliced pork lightly if needed, but do not soak it. Resting before slicing allows the juices that redistributed through the meat during roasting to settle rather than spilling out onto the board the moment a knife goes in — cutting immediately would lose more of that moisture than the meat can afford to give up.

Cut each cooled loaf in half to create 4 pieces about 8 inches / 20cm long. Split each piece horizontally like a sandwich roll. If the crumb is very airy, press it down lightly with your hand. Cuban sandwiches should compress well under the press, not resist it like a tall artisan loaf. This gentle pre-compression, if needed, is a small correction that matters for how the sandwich behaves later — bread with too much open, airy crumb structure resists the final hard press and won't flatten into the tight, layered cross-section this sandwich is known for.

Use straight yellow mustard, or mix the yellow mustard with the whole grain French mustard if you want that slight spin-off version. Spread on the inside of both top and bottom bread halves. Spreading mustard on both halves rather than just one distributes its sharp, tangy flavour evenly through every bite rather than concentrating it on only one side of the sandwich.

Layer the bottom half of each loaf with Swiss cheese, then sliced roast pork, then smoked ham, then pickle slices, then another layer of Swiss cheese. Close with the top half. Do not overstuff. The filling should be generous but still allow the sandwich to press flat and heat through evenly. Placing cheese both directly against the bottom bread and again near the top means melted cheese ends up binding the whole stack together from both sides once pressed, rather than pooling only in the middle.

Butter the outside of each sandwich lightly. Heat a large skillet, griddle, or plancha over medium heat. Place the sandwiches on the hot surface and weight them down firmly with another heavy skillet, bacon press, or foil-wrapped brick. Cook for 3–5 minutes on the first side until deeply golden and visibly compressed. Flip carefully, butter the second side if needed, press again, and cook another 3–5 minutes until crisp and the cheese is melted. The bread should be flattened, crisp, and deeply golden with clear contact browning. If the heat is too high, the bread burns before the cheese melts. Medium heat combined with genuine, sustained weight is what lets the sandwich compress and the cheese fully melt in roughly the same window the bread browns — too hot, and the crust darkens well before the centre has warmed through.

Cut each sandwich diagonally in half and serve immediately while hot and crisp. Diagonal slicing is the traditional presentation, and it also reveals the sandwich's layered cross-section clearly — a deliberate visual payoff for all the careful layering during assembly.