In a large non-stick saute pan, heat 1 tbsp cooking oil on medium heat.
Add in the mustard seeds and allow them to fry for ~30 seconds. You should start to see them sizzle and start popping.
Immediately add in the finely grated ginger, minced garlic, green jalapenos (if using), and chopped onions. Cook for a few minutes until fragrant and the onions start to become translucent. Mix frequently to avoid burning.
While the mixture is cooking, add all the Sauce ingredients above into a blender (I used a powerful blender such as a vitamix, but any blender should work).
Once the onions start to become transluscent, turn off the heat, and add all the contents of the saute pan (onion/garlic/ginger) into the blender containing the Sauce ingredients.
Blend on high until completely pureed into a smooth sauce.
Pour the sauce from the blender back into the saute pan, add all the Spices listed above, and mix to combine. Heat the sauce on medium-low until you achieve a gentle simmer. Cook uncovered for 10-15 minutes on medium-low heat.
If possible, immediately rinse the blender out so you can use it again to make the cashew cream.
To Make the Dish:
Add all the cauliflower florets into the sauce, toss, and cook, COVERED, for about 10 minutes on low heat or until the cauliflower florets are cooked and tender yet able to keep shape.
Remove the cover and cook again on medium heat, stirring occasionally, for up to about 10-15 minutes OR until the sauce reduces a decent amount and thickens in consistency. While you are waiting, prepare the cashew cream if using.
Season with additional salt if needed, turn off the heat, drizzle on 2 tbsp of cashew cream (if using), and garnish with some fresh chopped cilantro. Enjoy hot with some rice, Naan, or favorite tortilla.
Notes
The sauce itself is very creamy, and although it does not need the cashew cream, I recommend drizzling some on at the end prior to serving for some added richness.To Make Cashew Cream - Combine 1/2 cup soaked raw unsalted cashews + 1/4 cup water into a blender (preferably a high-powered blender). Blend on high until completely pureed. You should end up with smooth cashew cream (i.e. no pieces of cashews should remain). You will only be using 1-2 tbsp of the cashew cream in the recipe above. Store any remainder in the fridge or freeze.For a non-spicy version - Simply omit the red chili powder and green jalapeno.Coconut Milk - You can use lite coconut cream instead of the full-fat version. I've tried this and it still tastes great, just slightly less creamy.