One 6-pound first-cut beef brisket, trimmed so that a thin layer of fat remains
All-purpose flour, for dusting
Freshly ground black pepper
3 tablespoons corn or other mild vegetable oil
8 medium onions, peeled and thickly sliced
3 tablespoons tomato paste
Kosher salt
2 to 4 cloves garlic, peeled and quartered
1 carrot, peeled and trimmed