Turn on the saute function on the instant pot and add oil to the pot. Saute onion, carrots, and red pepper for a few minutes.
Push veggies to the side and add garlic, tomato paste, walnuts, and spices to the hot pot. Let those flavors bloom with a quick toast for about a minute, stirring to prevent burning.
Mix in split pigeon peas, broth, honey, and tomatoes.
Cover the instant pot with the lid, seal it, and set it to high pressure for 15 minutes.
After cooking, let it depressurize for 10-15 minutes. Release the pressure and open the lid. Blend with an immersion blender until smooth. The soup will be VERY hot so be careful here.
Mix in the cream and a small splash of vinegar. Adjust salt to taste and adjust thickness with additional broth if needed.