Colombo is the French West Indian version of curry powder. What sets it apart is the addition of an unexpected ingredient: toasted rice. The rice acts as both a flavoring and natural thickener. Toasting gives the rice a pleasing nutty flavor and makes it easier to grind.
Place the rice in a dry skillet and cook over medium heat until lightly browned, 2 to 3 minutes, shaking the pan to ensure even cooking (do not use a nonstick skillet for this). Transfer the rice to a bowl and let cool.
Add the cumin seeds, coriander seeds, mustard seeds, peppercorns, fenugreek seeds (if using), and cloves to the skillet and cook over