There are many different recipes that use different spices, and the proportions vary widely. In most recipes, the first two ingredients are garlic and coriander.
Basic Charmoula Recipe
1 garlic clove
1 tsp cumin seeds, toasted and ground
4 to 5 TB extra virgin olive oil
juice of 1 lemon, plus zest
1 jalapeño pepper, seeded and deveined
1 bunch coriander
salt to taste
pepper to taste
Mix the garlic, cumin, four tablespoons of the olive oil, lemon juice and jalapeño in a food processor. Pick coriander leaves from their stems. Add the lemon zest and coriander and season lightly with salt and pepper. Pulse mixture a couple of times, scraping mixture down from side of the bowl in between pulses. Add the remaining olive oil if needed. The mixture should resemble a rustic pesto. Place in tightly closed container and refrigerate for up to two days.
See also
Algerian Chermoula also suggests different uses including marinades and dressings.