Heat the Instant Pot on 'Sauté' mode. Once it is hot, add 1 tablespoon butter and once it is melted add onion, garlic and a pinch of salt. Cook until onion is softened about 3~4 minutes.Add the spices ground coriander, cumin, ginger, cinnamon, cayenne and pepper; cook until fragrant, about 1 minute.
Stir in tomato paste and cook for 1 minute. Add broth, 2 cups water and lentils, mix well making sure to scrape any stuck on bits from the bottom of the pot. Lock the lid and make sure that the steam valve is on 'Steaming' position. Turn off the 'Sauté' mode and turn on 'High Pressure/ Manual' mode. Cook for 6 minutes and once the timer sounds, let the pressure naturally release for 10 minutes, quick release the remaining.
Whisk the soup vigorously for 30 seconds, until smooth. Stir in lemon/ lime juice and season with salt. If the soup looks too thick, add ½~1 cup more water and heat on 'sauté' mode for 2~3 minutes.
Stove Top Method:
In a large saucepan, melt 1 tablespoon butter over medium heat. Add onion, garlic and salt; cook until softened about 5 minutes. Add ground coriander, cumin, ginger, cinnamon, cayenne and pepper; cook until fragrant, about 1~2 minutes.
Stir in tomato paste and cook for 1 minute. Add broth, water and lentils; bring to a simmer. Cook, stirring occasionally, until the lentils are soft and tender, about 18~20 minutes.
Whisk the soup vigorously for 30 seconds, until smooth. Stir in lemon/ lime juice and season with salt. If the soup looks too thick, add ½~1 cup more water and cook until heated through.
In a small skillet on medium heat, melt the remaining 2 tablespoons of butter, remove from heat and stir in mint and paprika. Ladle soup into individual bowls, drizzle each portion with 1tsp spiced butter, sprinkle with cilantro and serve.
Substitute vegetable broth with water if that is what you have on hand.
If you don't have tomato paste on hand, then use 3 tablespoons of either tomato sauce or tomato puree.
If you live at higher altitude, then increase the cooking time to 8 minutes if you want smooth cooked soup.
Make sure to scrape the bottom of the Instant pot well before pressure cooking to make sure that there is no 'burn' sign.
Leftover soup can be stored in the fridge in an airtight container for up to 3 days. Or freeze for up to 1 month.
Adjust the amount of spices added to the recipe to your taste preference.
To make the soup vegan, use oil or vegan butter instead of regular butter.