Blend 1/4 of the onion, green chile pepper, 1/4 cup water, cashews, garlic, tomato paste, and ginger together in an electric blender, adding extra water if necessary, until paste is creamy and has the consistency of a pesto. Set aside.

Combine cloves, green and black cardamom pods, bay leaf, cumin seeds, peppercorns, coriander, and cinnamon in a mortar. Smash using a pestle to break open spices slightly, 3 to 4 times. Thinly slice remaining onion quarters.

Turn on a multi-functional pressure cooker (such as Instant Pot®) and select Saute function. Add smashed spice mixture and toast until fragrant, about 30 seconds. Pour in oil followed by cashew pesto, onion slices, cauliflower, broccoli, tomatoes, chickpeas, carrot, red chile pepper, garam masala, turmeric, and chili powder. Stir. Cancel the Saute function. Close and lock the lid.

Select high pressure according to manufacturer's instructions; set timer for 5 minutes. Allow 10 minutes for pressure to build.

Release pressure using the natural-release method according to manufacturer's instructions, 10 to 40 minutes. Unlock and remove the lid. Stir in spinach and mix to help wilt. Stir in coconut milk and yogurt. Mix and serve with roasted cashews and cilantro on top.