Warm a dry skillet over medium heat and toast the Cumin Seeds, Coriander Seeds and Caraway Seeds for 1–2 minutes, shaking the pan, until fragrant and slightly darker; transfer to a mortar and pestle or spice grinder and grind to a coarse powder.
Remove stems and seeds from the Dried Red Chilies (wear gloves if you like) and soak the chilies in hot water for 20–30 minutes until softened; reserve about 1/4 cup of the soaking liquid.
Drain the softened chilies, then place them in a food processor with the Garlic and the ground toasted spices; pulse to begin breaking everything down.
Add a pinch (or two) of Kosher Salt to taste, then pour in the Lemon Juice and pulse again, using some of the reserved soaking liquid if the mixture seems too stiff.
With the processor running, slowly drizzle in the Extra-Virgin Olive Oil until the paste is smooth but still has some texture — stop when you reach your preferred consistency.
Taste and adjust: add more salt, lemon, or a splash of the chili soaking liquid to tame the heat or loosen the paste as needed.
Spoon the harissa into a jar, smooth the top, and pour a thin layer of olive oil over the surface to preserve it; refrigerate for up to 2 weeks or freeze portions for longer storage.
Tip: For a smokier flavor, char the chilies briefly over an open flame or under a broiler before soaking, and for milder harissa remove more of the chili seeds before blending.
