Acquasale (also acquasala) is Basilicata's quintessential peasant dish—stale bread soaked in water and dressed with raw onion, tomato, olive oil, salt, and oregano, sometimes with a poached egg slid on top, creating a dish of such extreme simplicity that it forces attention onto the quality of each ingredient. The dish is the Lucanian equivalent of Tuscan panzanella or pappa al pomodoro—a strategy for using stale bread (the most precious staple of a region where wheat-growing was hard-won from rocky mountain soil) that transcends its origins as survival food. The bread used is traditionally pane di Matera—the large, firm-crusted durum wheat loaf that becomes rock-hard when stale but softens beautifully when moistened. Chunks of day-old bread are briefly soaked in cold water (not drowned—the bread should soften but retain some structure), then dressed with sliced raw onion (the sharp, red tropea-type), chopped ripe tomatoes, a generous pour of Basilicata's peppery olive oil, dried oregano, and salt. The optional egg—poached or soft-boiled, placed on top so the yolk breaks over the bread—elevates the dish from snack to meal. Acquasale was the field lunch of shepherds and farmers, prepared wherever they happened to be with ingredients carried in a cloth bundle. It requires no cooking, no equipment beyond a bowl, and takes three minutes to prepare. Its quality depends entirely on the bread (must be proper durum wheat bread, not soft industrial bread), the tomatoes (must be ripe and flavourful), and the olive oil (must be excellent—it's doing all the flavouring).
Stale durum wheat bread, moistened with water. Raw tomato, raw onion, olive oil, oregano, salt. Optional poached or soft-boiled egg. No cooking required. Quality of ingredients is everything. Bread should soften but not dissolve.
The bread should be at least a day old—two days is even better for proper texture. Use the best olive oil you have—this is where it matters most. Red onion from Tropea or similar sweet-sharp variety is ideal. If adding an egg, poach it in the soaking water for efficiency. In summer, chill the soaking water for a refreshing version.
Using soft industrial bread (disintegrates). Over-soaking the bread (should be moist, not porridge). Using mediocre olive oil (it's the primary seasoning). Under-ripe tomatoes (must be at peak). Skipping the oregano (essential Lucanian note).
Touring Club Italiano, Basilicata in Cucina; Academia Barilla, Regional Italian Cooking