Remove fat and paper-thin membrane from surface of tenderloins. Horizontally cut each tenderloin to, but not through, the opposite side. Open to expose cut surfaces. Cover with clear plastic wrap. Pound tenderloins with a meat mallet from the centers to the edges, making 12x8-inch rectangles.
For stuffing, heat oil in a large skillet over medium-high heat. Add grapes, celery, pecans, shallots, garlic, 1 tablespoon fresh rosemary or 1 teaspoon dried rosemary, 2 teaspoons fresh thyme or 1/2 teaspoon dried thyme, 1/4 teaspoon salt, cardamom, and 1/4 teaspoon ground pepper. Cook and stir for 3 to 5 minutes or until shallots are tender. Remove from heat; cool 5 minutes.
Add bread crumbs and enough brandy or broth to moisten stuffing mixture. Spread half of the mixture evenly over each tenderloin to within 1 inch of edges; roll each up from a short side and tie with string, if necessary. Place rolled tenderloins, seam sides down, on a rack in a shallow roasting pan. Rub cracked pepper and dried thyme or rosemary onto tenderloins. Lay a bacon slice lengthwise over each rolled tenderloin. Insert a meat thermometer into the center of one rolled tenderloin.
Roast, uncovered, in a 425 degree F oven for 25 to 35 minutes or until thermometer registers 160 degrees F. Transfer to a platter. Cover with foil and let stand about 10 minutes at room temperature. Remove string; cut into 1/2-inch-thick slices.
Meanwhile, combine flour, paprika, 1/2 teaspoon salt, and 1/4 teaspoon pepper in a small saucepan. Stir in half-and-half or cream, white grape juice concentrate, and the 3 tablespoons brandy. Cook and stir until slightly thickened and bubbly; cook 1 minute more. Serve with sliced pork rolls. If desired, garnish with additional grapes and/or thyme or rosemary sprigs. Makes about 32 slices. (Nutrition facts are per slice.)