Place the beans, water, olive oil, garlic, sage, and red pepper flakes in the Instant Pot. Close the lid, turn the lever in the back to "seal". Pressure cook on high for 22 minutes. When finished, allow to natural release for ten minutes, and then carefully finish with quick release. Gently shake or tap the pressure cooker, and THEN carefully open away from you. Gently, stir in the salt and kale, it will collapse in a minute or two. Transfer the beans to a large serving bowl. Serve each bowl with any of the suggested toppings you like.
Preheat oven to 225F / 110C, with a rack in the bottom. Place the beans in a large ovenproof casserole or pot. Add the water, olive oil, garlic, sage, and red pepper flakes and bring to a simmer on the stove top. Remove from the heat, cover, leaving a tiny crack, then transfer to the oven.
For reference, this is the Instant Pot I used for this recipe: Instant Pot DUO Plus 6 Qt 9-in-1