Set the Instant Pot to sauté mode for 7 minutes. Add the oil. Once hot, add the onion, garlic, and ginger. Cook for 3-4 minutes, or until the onions start to caramelize and become soft. Add the dried fenugreek leaves, garam masala, turmeric, chili, cumin, and salt. Continue to cook for another 2 minutes, stirring regularly to make sure it doesn't burn. Add a couple of tablespoons of water and scrape the bottom to make sure nothing is sticking to it, this will prevent the Instant Pot from giving you a "burn" message.
Add the diced tomatoes, maple syrup, and cauliflower florets. Secure the lid and close the vent to Sealing. Press the Pressure Cook button and adjust the time to 2 minutes. The Instant Pot will take about 10 minutes to come to pressure, then cook under pressure for 2 minutes.
Once the program is finished and you have heard the beeps, wait 1 minute and release the pressure. Stir in the non-dairy yogurt and stir to combine. Taste the sauce and adjust saltiness if needed.
Serve hot with rice, naan, or tofu, and top with fresh parsley and roasted cashews.
This Instant Pot cauliflower will keep for up to 3 days in the refrigerator. Reheat over medium heat in a saucepan, or in the Instant Pot on the "Sauté" or "Keep warm" function.