- 4 tablespoons olive oil
- 2 tablespoons butter
- 4 onion, sliced thin
- 3/4 teaspoon salt
- 1 1/2 pounds (1/2-inch-thick) calf's liver, cut into 1 1/2-inch squares
- 1/4 teaspoon fresh-ground black pepper
- 6 sage leaves
- In a large nonstick frying pan, heat 3 tablespoons of the oil with 1 1/2 tablespoons of the butter over moderately high heat. Add the onions and cook, stirring occasionally, for 10 minutes. Stir in 1/4 teaspoon of the salt. Reduce the heat to moderate and cook, stirring frequently, until the onions are well browned, about 5 minutes longer. Remove.
- Sprinkle the liver with the remaining 1/2 teaspoon salt and the pepper. In the same pan, heat the remaining tablespoon oil and 1/2 tablespoon butter over high heat. When the pan is very hot, add the liver and sage. Cook, stirring, until just done, 1 to 2 minutes. Remove from the heat, return the onions to the pan, and toss.