Sear the Beef: Start your Instant Pot by setting it to sauté mode. Add a little oil, then toss in your beef cubes. Sear those chunks until they're nicely browned on all sides. This step locks in the flavor and gets your stew off to a bold start! If you're making a large batch like me you'll need to cook the meat in two batches to not overcrowd the pot.
Add the aromatics: Once the beef is golden and irresistible, add the onion, garlic, celery, tomato paste, and give it a good stir.
Deglaze with Balsamic Vinegar: Pour in the balsamic vinegar and give it a good stir. This step is all about scraping up those flavorful bits from the bottom of the pot.
Rosemary: Toss those sprigs of fresh rosemary into the pot.
Broth & Fish Sauce: Pour in the beef broth and add our secret ingredient—fish sauce! Stir everything together. Make sure to get that tomato paste fully dissolved into the liquid.
Stir and Start Instapot: Stir everything together, making sure the tomato paste is fully incorporated. Close and lock the Instapot lid and set mode to Soup/Stew for 30 minutes. Once the time is up, let the instapot naturally release the pressure, this takes about 10 minutes.
Potato & Carrot: Now, it's time to add the potatoes and carrots. These hearty veggies will soak up all that flavor and become tender in no time. Secure the lid and set the Instant Pot to stew for another 10 minutes.
Cornstarch Slurry & Peas: While the potatoes and carrots are cooking, let make a cornstarch slurry. This add a little thickness too the broth. Add 2 tablespoons of water to 2 tablespoons of cornstarch and mix to combine. After the timer goes off, manually release the pressure this time. Remove the Rosemary stems and add the slurry and the peas. Give them a gentle stir and let them warm up in the stew. No need to cook them for long; we want them to stay bright and vibrant.