Rinse the meat and pat dry with a paper towel.
Salt and pepper all sides.
In a cast iron (or oven-safe) pot, heat 1 T olive oil over medium-high heat.
Place the seasoned roast in the pot and brown on all sides.
Set the meat aside on a plate.
Chop and saute the onions in the same pan, stirring frequently. Be sure to scrape the pot to get all the good bits and mix them in with the onions.
Once the onions are translucent, place the roast on top. Add the beef broth, chopped rosemary, and potatoes if you are including them.
Cover and place in the oven for 1.5 to 2 hours. (about 20 minutes per pound)
About 1 hour before the roast is done, add the carrots to the pot.
Remove the pan from the oven and let the meat rest for about 10 minutes.
Slice and serve.