How to Make It
Select SAUTÉ setting on a 6-quart programmable pressure multicooker (such as Instant Pot). (Times, instructions, and settings may vary according to cooker brand or model.) Select HIGH temperature setting, and allow to preheat. Add 1/2 cup of the butter to cooker, and heat until sizzling. Add onion, garlic, ginger, turmeric, and jalapeño. Cook, stirring occasionally, until onion is tender and beginning to brown around edges, 13 to 15 minutes. Add tomatoes, lentils, and salt; stirring well to coat in spice mixture. Pour 3 cups of the water over lentils. Cover cooker with lid, and lock in place. Turn steam release handle to SEALING position.
Select MANUAL setting on HIGH pressure for 20 minutes. (It will take 5 to 15 minutes for cooker to come up to pressure before cooking begins.)
While lentils cook, heat remaining 1/4 cup butter in a large skillet over medium-high until just beginning to brown around edges of skillet, about 5 minutes. Add cumin seeds, cayenne, garam masala, and, if desired, asafetida. Cook, stirring constantly, until cumin seeds darken, about 1 minute. Immediately remove from heat, and sprinkle with remaining 1/8 teaspoon water to stop cooking process.
Let pressure release naturally for 10 minutes. Carefully turn steam release handle to VENTING position, and let steam fully escape (float valve will drop). (This will take 5 to 15 minutes.) Remove lid from cooker, and turn off cooker. Let stand 10 minutes.
Stir cumin mixture, heavy cream, and lime juice into lentil mixture. Divide among 4 bowls, and garnish with cilantro leaves. If desired, spoon ghee on top of each serving. Serve with naan.