slow cooker skinny cheesesteaks

canola oil

grass-fed beef chuck roast

kosher salt, divided

freshly ground black pepper

dry marjoram or Italian seasoning blend

large onion, sliced

portabello mushrooms, stems removed, gills scraped out and sliced

dry red wine, such as Malbec

Worcestershire sauce

each red and yellow bell peppers, cored and sliced

jarred marinara sauce

slices or ¾ cup shredded Provolone cheese (3 oz)

whole grain buns such as Ezekiels, toasted if desired