Heat the oil over medium-high heat in a Dutch oven.
In a large bowl, whisk the flour, salt, and pepper. Add the beef stewing cubes and stir until well-coated. It’s fine if some flour remains loose in the bowl.
Add the beef and any remaining flour to the hot pot. Cook over medium-high heat for 10 to 12 minutes, stirring often, until the meat is evenly browned.
Pour in the beef stock, using a spatula or wooden spoon to scrape up the browned bits from the bottom of the pot. These bits, called fond, add rich flavour to the stew.
Add the onions and stir. Bring to a light boil, then reduce the heat to medium-low. Adjust as needed to maintain a gentle simmer, cover, and cook for 90 minutes.
After 90 minutes, add the carrots and potatoes. Raise the heat to bring the stew to a light boil, then reduce to a lively simmer. Cover and cook for 45 minutes.
Add the summer savory and stir to combine.
In a small jar, shake the cornstarch and cold water until smooth, then pour it into the pot and stir well. Raise the heat to a light boil and cook for 3 to 4 minutes, until the gravy thickens. Serve hot with buttered bread, rolls, or biscuits.
Notes
Don’t worry if some flour doesn’t stick to the beef. Tip all of it into the pot as it helps thicken the stew later.
Make sure the oil is hot before adding the beef so the cubes start to sear right away instead of soaking up oil.
It’s normal for a bit of flour to stick to the bottom of the pot while browning. Once the stock goes in, it will loosen up and enrich the gravy.
Storage
Store leftover beef stew in an airtight container in the refrigerator for up to three days. Reheat gently on the stove over low heat, adding a splash of stock or water if the gravy thickens too much.
Beef stew can be frozen in a container or zipper-top freezer bag for up to three months, but the potatoes may soften after thawing.