A serranito is a popular sandwich in Southern Spain and MAD, one of Houston’s go-to Spanish restaurants, serves up one of the best. The secret to this sandwich is in the pork. Both the secreto and the Jamón Ibérico de Bellota come from Spain’s acorn-eating pigs. Secreto is a “secret” cut of boneless meat from behind the pork shoulder. While it’s well-worth the search, if you can’t find secreto then you can omit it from the recipe.
In a large saucepan, melt the butter over moderate heat. When the butter starts to sizzle, add half of the onion and cook, stirring occasionally, until the onion is soft and starting to turn translucent, about 2 minutes. Add the remaining onion and cook until the onions are translucent and tender. Reduce the heat to moderately-low and cook, stirring occasionally, until the onion is very tender and caramelized, about 40 minute.
In a large nonstick skillet, heat 1 tablespoon of olive oil over moderate heat. Add the bell pepper and cook, stirring occasionally, until peppers are tender, about 10 minutes. Scrape the pepper into a small bowl.
In the same skillet, heat 2 teaspoons of olive oil over high heat. Sear the secreto, turning, browned, about 2 minutes per side. Let cool for 5 minutes, then thinly slice. Do not overcook.
Slice the bread in half lengthwise. Spread the tomato puree on the cut sides, then drizzle with more olive oil. Layer the slices of secreto, Manchego and Jamón Iberico on the tomato puree. Top with caramelized onions and bell peppers. Season with salt and pepper, then cut into two-inch lengths; serve.
NOTE Pan de Cristal, or ‘glass bread’, is a Spanish version of Ciabatta bread. The crust is thin, crispy and delicate. When you slice it, it ‘breaks’ like glass. It’s difficult to find this bread outside of Spain. You can easily substitute this bread with a crusty baguette of your choice.