Melt the butter in a small saucepan on very low heat. Add the black cumin seeds, serrano pepper, garlic powder, and cayenne pepper powder, and allow the flavors to combine for about 30 seconds. Remove from heat and add salt and lemon juice, mix well.
Preheat the oven to 200 degrees. In a large mixing bowl, combine the nuts and chickpeas with the spiced butter. Place them in a single layer on a shallow cookie sheet, and bake for 20 minutes or until toasty.
Place the puffed rice on another cookie sheet, and bake for about 8 minutes, or until warm and toasty. Combine the roasted puffed rice with the nuts and cover to keep the mixture warm. Serve immediately. (Note: Godbole serves these in paper cone cups.)