Heat the oil in a large wok or skillet over medium to medium-hight heat.
Add in the garlic, mustard seeds, cumin, chili powder, salt, tumeric, dried chilies and curry leaves. Cook for about 1 minute, stirring frequently to make sure the spices are well mixed and evenly coated in the oil, and to prevent the spices from burning.
Add in the peanuts and cook for 1 minute, stirring frequently.
Add in the cashews and cook for 2 minutes, stirring frequently. The nuts should be lightly toasted by this point.
Add in the coconut and cook for 1 minute, stirring frequently.
Turn the heat to low, and add in the puffed rice. Cook for about 3-5 minutes, stirring frequently to coat the puffed rice with the oil and spices.
Allow to cool. At this point, this spicy puffed rice can be saved in an airtight container at room temperature for several days.
When serving, garnish with mint leaves and grate some lime zest over it. Serve with a slice of lime, to be squeezed right before eating (so it does not make it soggy).
You may want to remove the garlic cloves before serving.