In medium saucepan over medium heat, combine all ingredients and bring to boil. Reduce heat to low and simmer until mixture has thick, jam-like consistency, about 1 hour.
Slice turkey breast diagonally into eight (2-ounce) portions. Pound these with meat mallet between sheets of wax paper to 1/2-inch thick.
In shallow glass baking pan, combine flour, polenta, cumin, chili powder, coriander, garlic powder, salt, and pepper.
In a large stainless steel sauté pan over medium heat, warm oil. Dredge turkey medallions in seasoned polenta mixture, add to pan, and cook (working in 2 batches if necessary) until golden-brown, 3 to 5 minutes per side.
Place 1 turkey medallion on each plate, top with 2 tablespoons tomato jam, and place second medallion on top. If using veal demi-glace, spoon 2 tablespoons around each medallion.