Put the coriander, cumin, and cardamom seeds into a dry skillet. Toast the spices lightly over medium heat, shaking the pan frequently, just until they become fragrant, about 4 minutes. Let these cool for a few minutes, then grind fine in a spice grinder or with a mortar and pestle.
Put the chiles and garlic in a food processor and pulse a few times until they are fairly finely chopped. Add the cilantro, parsley, the mixture from the spice grinder, ground cloves, lemon zest, lemon juice, 1 tsp kosher salt, and a few shakes of black pepper. Pulse until all is finely chopped into a rough puree.
With the motor running, drizzle in the olive oil. Stop before the sauce is completely blended smooth. add the flesh of the avocado and continue to mix until completely combined, but still textured.
Taste and adjust the seasoning with salt and pepper. Pour into a bowl and stir in a few spoonfuls of Greek yogurt.
Store in the fridge for up to a week.
based on the Spiced Green Sauce from Joshua McFadden's Six Seasons