Sauté the Base: Set your Instant Pot to the “Sauté” function and heat the oil. Add the chopped onion and cook for 2-3 minutes until softened. Stir in the garlic and ginger, cooking for another minute until fragrant.
Add Veggies and Beans: Toss in the diced carrots, rinsed mung beans, cumin, turmeric (if using), and a pinch of salt and pepper. Stir everything to coat the beans and veggies in the spices.
Pour in Liquid: Add the 4 cups of vegetable broth (or water). Give it a quick stir, scraping the bottom to deglaze any bits stuck from sautéing.
Pressure Cook: Cancel the “Sauté” mode, secure the Instant Pot lid, and set the valve to “Sealing.” Cook on high pressure for 20 minutes. (Whole mung beans typically take 18-20 minutes in the Instant Pot without soaking, and this ensures they’re soft enough for soup.)
Release Pressure: Once cooking is done, let the pressure release naturally for 10 minutes, then carefully move the valve to “Venting” to release any remaining pressure.
Finish the Soup: Open the lid and stir. The mung beans should be tender and starting to break apart. For a creamier texture, use an immersion blender to blend part of the soup (or all of it, if you prefer smooth). Stir in the coconut milk if using, and adjust seasoning with more salt and pepper to taste.
Serve: Ladle into bowls, top with fresh cilantro, and add a squeeze of lemon juice if you like a zesty kick. Pair it with crusty bread or enjoy it solo!