Pressure Cook for 7 minutes with a quick pressure release: Pour 1 cup of water into an Instant Pot or other pressure cooker. Add a vegetable steaming basket, fill it with potato chunks, and top with the chopped kale. Lock the lid and pressure cook at high pressure for 7 minutes in an electric pressure cooker or stovetop PC (Use "Manual" or "Pressure Cook" mode in an Instant Pot). When the cooking time is over, quick release the pressure. Once the pressure is released, unlock the pot and open the lid away from you to avoid the hot steam.

Melt butter and sauté the onions: Carefully lift the steaming basket out of the pot, and set aside on a heatproof surface (I use a large plate). Pour the water out of the pot liner, put the pot liner back into the pressure cooker base (or back on the stovetop), add the butter, and melt the butter over sauté mode - high (medium-high heat on the stovetop). Once the butter is melted, stir in the onions. Sauté until the onions soften and start to brown around the edges, about 8 minutes.

Mash the potatoes and carrots: Turn off the heat and add the potatoes and kale. Sprinkle the potatoes and kale with the salt, and give them a rough mash, stirring to coat with the butter and salt. Add the cream. Mash again, starting gently - the cream will splatter - and keep mashing and stirring until the cream is blended in and the potatoes are smooth. Transfer to a serving bowl, serve, and enjoy.