In my wonderful, ole slow cooker, this almost 4 pound roast became Italian beef after a few spices and several hours on low.
This batch had Hot Peperoncino rings and it was a HIT!

In slow cooker, with amounts that suit YOUR taste-buds:
Beef Roast
Kraft Zesty Italian Salad Dressing, or your own homemade, drizzled over roast
Peperoncino rings, cooked with roast or added later or both
Italian Seasoning, 1 tsp to 1 Tbsp, your call
Sweet Basil, a good sprinkle
Garlic Powder , a good sprinkle
Onion Powder , a good sprinkle

In hot skillet:
Olive oil, 1 or 2 Tbsp
Sliced green peppers
Sliced onion
Saute until you like them.

Toppings, optional:
Monterrey jack or your favorite cheese
Salt and pepper
Peperoncino  rings

Image above shows a serving on home-bread-machine-made Italian Herb & Cheese bread, layered with Monterrey Jack, sauteed bell pepper and onion and hot Peperoncino rings.
On open-face toast, hamburger buns or hoagie rolls, this sandwich is a crowd pleaser!
Pair with a green salad or sliced veggies, or like some folks, Seasoned Fries!!