Heat dutch oven over medium-high heat for several minutes. Add 1 tbsp of the oil and when it’s shimmering hot, add the beef. Season it with ¾ tsp salt and ¼ tsp pepper. Let it brown undisturbed until it releases easily from the pan, about 4-6 min. Remove to a plate. Don't bother wiping out the dutch oven.
Add remaining oil to the pot along with onion, carrots and celery. Season with 1 tsp more salt. Cook until the vegetables are soft, about 5 minutes.
Add tomato paste and let it cook until it turns a shade darker, about 2 minutes. Add broth and return beef to the pot. Add zucchini, ½ tsp black pepper and 2 cups of water. Cover, bring to a boil, then reduce heat to low and simmer until beef is tender, about 2 hours.
Taste and add more salt as needed (it will depend on how salty your broth was).
Video
Notes
Instant Pot / Pressure cooker version: pressure cook for 40 minutes on high pressure instead of simmering after you add the broth.Slow Cooker / Crockpotversion: slow cook on high setting nstead of simmering after you add the broth.Beef options: bone-in or boneless steak, short ribs or boneless stewing beef are all great here.Peas are great if serving right away, but tend to get mushy and taste off if you're serving this soup over the course of a few days. Omit the peas if you don't like the mushy pea flavor.