Heat walnuts in a small nonstick skillet over medium-low heat, stirring occasionally, 5 to 6 minutes or until lightly toasted.
Remove rolls from packages. (Do not separate rolls.) Cut rolls in half horizontally, creating 1 top and 1 bottom per package. Spread preserves on cut sides of top of rolls; sprinkle with walnuts. Spread mustard-mayonnaise blend on cut sides of bottom of rolls; top with beef and cheese. Sprinkle with salt and pepper to taste, if desired. Cover with top halves of rolls, preserves sides down, and wrap in aluminum foil.
Bake at 325° for 20 to 25 minutes or until cheese is melted. Slice into individual sandwiches.
Note: To make ahead, prepare recipe as directed through Step 2, and freeze up to 1 month. Thaw overnight in refrigerator, and bake as directed in Step For testing purposes only, we used Rainbo Dinner Time Rolls, Hellmann's Dijonnaise Mustard, and Boar's Head Londonport Top Round Seasoned Roast Beef.
Wow!! these were Great! made a mayo mixture with dijon, garlic powder and horseradish. really popped with the peach preserves. had leftover tenderloin (sliced) , and swiss cheese on a french bread roll. picky daughter even liked with the preserves!!!! will make again.
One of the best things I have made yet!! Great aspect is you can make them early in the day, wrap in foil, and pop in as guest arrive (about 15 min)- they are fresh, delicious, hearty, and look like you were busy for hours!! My 10 year old loved them as well, so kid friendly as long as they like nuts.