Put a pan on medium high heat and dry roast the peppercorns, cloves, black cardamom, and cinnamon bark until fragrant and toasty. This takes about 2-3 minutes.
Transfer the whole spices to a plate to cool and add the cumin seeds to the same pan stirring frequently until evenly toasted - another 2 minutes or so. Add to the same plate as the other whole spices and let cool a little.
Grind to a powder in a small blender along with the nutmeg and mace, store in an air tight jar, and use as needed in your recipes.
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Notes
Toasting the cumin seeds separately ensures that they don't burn. The larger whole spices need a little more time and space to be able to roast.
Nutmeg and Mace are delicate spices and don't necessarily need to be roasted.
You can absolutely add coriander seeds but for them I would recommend adding half the amount of cumin seeds.