Set Instant Pot to SAUTE, add heat the oil. Add onions and a pinch of salt and sauté until softened, 5-7 minutes.
Stir in garlic, ginger, coriander, turmeric, cumin, and cayenne and cook for another minute until fragrant.
Hit the CANCEL button and add split peas, water, tomatoes, salt and stir to combine, scraping up any browned bits from the bottom of the Instant Pot.
Cover and seal the lid - turn the vent to sealing. Press the MANUAL (high pressure) button and set the timer to 10 minutes. It will take about 15 minutes for Instant Pot to come to full pressure, then the display will show a countdown timer.
Meanwhile, make your toppings.
In a small bowl, combine lime zest and juice, red onion, sugar, and a large pinch of salt. Massage the onion for 1 minute to help it soften.
Mix yogurt and 2 Tbsp. water in a small bowl; season with salt and pepper, to taste.
Once the 10 minutes are up, allow the pressure to release naturally for 10 minutes, then release any remaining pressure.
Open the lid, stir in the cilantro and season with additional salt and pepper, to taste.
Serve dal over rice drizzled with yogurt and topped with pickled onion and additional cilantro.