In a large, heavy skillet, heat 2 tablespoons of the oil over medium-high heat. Add the meat or fish in a single layer. Cook for about 5 minutes on each side or until browned; transfer to a plate and set aside. Add the pears and cook, stirring, for about 2 minutes; remove from the skillet. Add the onion and the remaining oil to the skillet and cook until soft, stirring occasionally, about 2 minutes. Stir in the curry powder and flour. Add the broth and ketchup and heat to boiling. Return the meat or fish and pears to the pan and coat with the sauce. Reduce heat to medium-low and simmer, covered, 15 to 20 minutes for the chicken, 25 to 30 minutes for the pork, or 10 minutes for the salmon. Season with salt and pepper to taste and divide among 4 plates.