Preparation

• Pat the lamb dry with paper towels and season generously with salt and pepper.
• Heat the oil in a 12-1/2-inch cassola (on a heat diffuser if recommended by the manufacturer) over medium-high heat. Working in batches so as not to crowd the cassola, brown the lamb on all sides, 8 to 10 minutes per batch, adding more oil as needed. Transfer each batch to a platter and cover with foil to keep warm.
• Reduce the heat to medium, add the onion, and cook, stirring frequently, until translucent, 3 to 4 minutes. Add the tomatoes, reduce the heat to low, and cook, uncovered, stirring frequently and then tapping down the mixture with the back of a wooden spoon until thickened and darker, 10 to 15 minutes, adding a little water as necessary to keep it from drying out and sticking.
• Return the lamb to the cassola and turn to coat well. Drizzle with the wine, stir, and cook for 1 minute. Add the stock and bay leaf, increase the heat to medium high, bring to a boil, and then reduce to a simmer. Cover with a large pot lid or foil, leaving it slightly ajar, and cook, stirring occasionally, for 10 minutes if using bone-in lamb or 30 minutes if using boneless.
• Add the potatoes and olives, replace the lid slightly ajar, and cook over low heat until the lamb and potatoes are fork-tender, 45 minutes to 1 hour, adding more stock if needed to keep the sauce moist. Season to taste with salt and pepper.
• Serve from the cassola with the bread, and be sure to warn everyone about the olive pits.