Set your Instant Pot to Sauté More and let it heat until the display reads HOT — this takes about 8 minutes but ensures proper browning.
⏱ 8 min
Pat the chuck roast completely dry with paper towels, then season one side generously with salt and pepper. Pour the olive oil into the hot pot, swirling to coat the bottom evenly.
Place the seasoned side of the roast down in the pot — it should sizzle immediately. Season the top side while it browns. Let each side develop a deep brown crust for exactly 10 minutes without moving it.
⏱ 20 min
Transfer the browned roast to a plate and set aside. Drop the sliced onions into the same pot and cook, stirring occasionally, until they soften and pick up some of the browned bits. Season lightly with salt and pepper.
Stir in the minced garlic and cook for 30 seconds until fragrant. Add the mushrooms and cook for 2 minutes until they start to release moisture, then season with a pinch of salt.
⏱ 2 min 30 sec
Pour in the wine or vinegar and immediately scrape up all the browned bits from the bottom with a wooden spoon — this fond is pure flavor for your gravy.
Stir in the chicken stock, soy sauce, fish sauce, rosemary, thyme, and bay leaves. Taste the liquid and adjust seasoning — it should be well-seasoned since it will become your gravy base.
Nestle the chuck roast back into the pot along with any accumulated juices. Lock the lid in place and turn the venting knob to the sealing position.
Pressure cook on High for 45 minutes, then allow the pressure to release naturally — don't touch the valve. The full natural release takes about 25 minutes and keeps the meat incredibly tender.
⏱ 1 hr 10 min
Carefully remove the roast to a cutting board and tent with foil to rest. Add the quartered potatoes to the cooking liquid, then stack the carrot chunks on top.
Seal the lid again and pressure cook on High for 4 minutes, then immediately quick-release the pressure. The vegetables should be tender but not mushy.
⏱ 4 min
Whisk the cornstarch with cold water until smooth. Switch to Sauté mode and stir the slurry into the gravy one-third at a time, simmering until it reaches your desired thickness — about 2-3 minutes total.
Slice the rested roast against the grain into thick slices. Arrange on plates with the vegetables and spoon the rich gravy over everything.