Prepare brussels sprouts- wash, pat dry, and trim the bottom ¼ inch off the stem. Slice in half *see note 1.
Prepare the Instant Pot– place 1 cup (6 quart) or 1.5 cups (8 quart) water into the stainless steel insert of your Instant Pot. Place the trivet on top, and a steamer basket on top of the trivet. Add the brussels sprouts to the steamer basket.
Cook the sprouts– Place the lid on the Instant Pot, set the steam release handle to the ‘sealing’ position, and pressure cook on high pressure for 1 minute (0 minutes for small or frozen sprouts).
Quick pressure release- When the cooking cycle has completed, perform a quick pressure release: carefully transfer the steam release handle to the ‘venting’ position to release the pressure.
Melt the butter- Using oven mitts, transfer the trivet and steamer basket containing the brussels sprouts aside. Carefully decant the water from the stainless steel insert, then return to the Instant Pot. Select the ‘sauté’ function, and add the butter and salt to the stainless steel insert.
Sauté the sprouts– Once the butter is melted, add the brussels sprouts to the Instant Pot. Cook, stirring occasionally, for 2-3 minutes, until sprouts are evenly coated in the butter.
Garnish + enjoy- Sprinkle with sliced almonds and (optional) flaky sea salt, remove the stainless steel insert from the Instant Pot, and enjoy.