Palermo's seared spleen and lung sandwich topped with ricotta or lemon is adventurous street food. A carnivore high protein mediterranean tradition that's been nourishing Sicilian families for centuries.
Prepare the beef spleen and lung by thoroughly rinsing under cold running water and trimming any excess fat or connective tissue.
Bring a large pot of water to a simmer (medium heat), add the spleen and lung, and poach gently for 30–35 minutes; do not boil.
Remove the organs, allow to cool briefly, then slice as thinly as possible for tender texture.
Heat olive oil in a large skillet over medium-high heat. Add the sliced spleen and lung, and sear for 5–7 minutes, turning occasionally, until browned but still moist.
Split the French rolls; pile warm offal into each roll. Top with a generous spoonful of fresh ricotta or squeeze of fresh lemon. Sprinkle with sea salt and black pepper to taste. Serve immediately.