Tweak according to your preference. And that means you have to familiarize yourself with the flavor and aroma of each and every ingredient. When you've done that, you'll understand that "spicy" and "hot" shouldn't be used interchangeably when describing spices.
1tablespoonpeppercornsblack or white, or a combination
1half-inch stick cinnamonbroken into small pieces
1dried chilioptional
½teaspoonwhole cloves
1bay leaf
¼teaspoongrated nutmeg
Instructions
Place all the ingredients, except the bay leaf and nutmeg, in a thick-bottomed skillet.
Over medium-low heat, toast the spices, tossing often, until they turn twice (or even thrice) as dark as their original colors (see notes after the recipe).
Cool the toasted spices.
Grind the toasted spices and bay leaf using a mortar and pestle, or a mini-food processor. How fine or coarse the grind should be depends entirely on how you intend to use the garam masala.
Stir in the grated nutmeg.
The garam masala is ready to use.
Notes
When toasting spices, keep the heat low. You're toasting them to heighten the flavor and make them give off a smoky aroma. There is, however, a thin line between darkly toasted and burnt. The best way to avoid burning the spices is to keep the heat low. Store excess garam masala in an air-tight jar at room temperature away from the sun. Use within a week or two.