Turn on your Instant pot (IP) to sauté mode on high. Add 2 tablespoons of oil and allow to heat for about 2 minutes, until oil is hot and sizzling.
Remove the chicken from the packaging and pat it dry with paper towels. Season with salt and black pepper. Add chicken to IP and let sear on each side until brown but not cooked through, about 2 mins per side. Once browned on both sides, remove from IP and, place on a plate, set aside.
Add a tablespoon of oil to the IP. Add the onions and cook on sauté mode for 2-3 mins until onions begin to soften. Add the garlic and allow to cook for about 30 seconds until you smell the fragrance of the garlic. Add all the dry spices, and stir into your onion and garlic mixture for 30 seconds to toast the spices. Add tomato paste, diced tomatoes, and 1 ½ cups broth or water to the pot.
Turn off Instant Pot. Scrap the bottom of your IP to ensure no brown "yummy bits" are stuck to the bottom but incorporated into your sauce. Return chicken to the IP and nestle chicken and juices into the sauce. Place the kale on top of the chicken and sauce. Add your IP steamer basket to the top of the kale.
Season your sweet potato cubes with olive oil, salt, and black pepper. Toss to coat evenly. Wrap sweet potatoes in parchment paper, so the steam can't escape. Place sweet potatoes into your IP steamer basket. Place the lid on the Instant Pot and lock it into place. Turn on Pressure Cook on high and set timer for 10 minutes. Allow to release naturally for 5 minutes, then quickly release the remainder of the steam.
Remove the steamer basket and carefully open up your parchment paper. Mash your sweet potatoes in the parchment (for easy cleanup). Remove chicken pieces from pot (internal temp of at least 165˚) and place on top of sweet potato mash. Add the lemon juice to the kale and sauce and stir. Taste the sauce and add additional salt or pepper. Pour sauce over chicken, garnish with fresh parsley or fresh cilantro, and lemon slices. Optional: dollop of labneh or greek yogurt.