Step 1

Hit "saute" button on Instant Pot. Add sausage and cook until meat crumbles and begins to brown, about 5 minutes. Add onion, celery and garlic and cook until softened, about 5 minutes.

Step 2

Add stock, lentils, red pepper flakes, tomatoes and stir.

Step 3

Place lid on Instant Pot and make sure the release valve is in the "sealing" position. Press "manual" button and set timer for 12 minutes.

Step 4

The Instant Pot will warm up for about 10 minutes and then start cooking. After 12 minutes, quick-release by flipping the release valve to “venting."

Step 5

Add kale and vinegar. Stir to combine and season with salt and pepper, to taste. Sprinkle with chopped parsley before serving.