Step 1Using a paring knife, cut and peel papery skin off onions. Cut off stem top. Slice onions down center from stem top to root bottom, using root bottom to hold onion together. Place onion halves flat side down and slice lengthwise from stem top to root bottom in 1/4-inch thick slices, then cut crosswise in 1/4-inch pieces. Discard root bottoms. Melt 1 tablespoon butter in skillet over medium-high heat and saute onions until softened, about 5 minutes, stirring frequently. Place onions in bowl and set aside.
Step 2Cut meat into bite-size pieces and set aside. Peel apple and cut off 4 wedges, leaving just apple core. Discard core and cut each wedge into 1/2-inch chunks. Add raisins. Set aside with onions and meat.
Step 3Place broth in small saucepan and heat until simmering. Turn off heat and let sit on burner while you start your sauce.
Step 4Melt remaining butter in 2 1/2-quart saucepan over low heat and stand right there and watch the butter melt (butter can brown quickly and you don't want this to happen); tilt saucepan so butter coats bottom of pan. Sprinkle flour and curry powder over butter and, using a large spoon, stir constantly, all over the bottom of the pan, so butter, flour and curry powder get well blended. Now slowly add hot broth or water to butter mixture, stirring constantly so mixture blends well. Turn heat to medium and stir until thick, smooth and creamy, about 3 minutes. Now stir in salt and taste. Add more if needed. Add meat, apple and raisins and continue to stir and cook sauce a few more minutes or until meat is thoroughly heated.