1) Add cumin seed, coriander seed, cloves, cardamom, and peppercorns to a dry skillet over medium heat. Toast until fragrant, about 3-4 minutes.
2) Add those spices to a spice grinder with other spice mixture ingredients and pulse until ground.
3) In a large pot, melt butter over medium heat. Then add diced onions, peppers, garlic, and ginger. Cook until veggies are soft, about 5-6 minutes.
4) Add ground spice mixture to pot along with cashews and stir together. Cook for about a minute to heat spice mixture.
5) Add coconut milk and remove from heat. Add mixture to blender and blend until smooth.
6) Return curry to the pot and bring to a simmer. Add chickpeas and spinach and simmer for a few minutes to combine flavors.
7) Season with lime juice and a pinch of salt if necessary and serve over rice garnished with cilantro.