A recipe for harissa sauce from Saveur calls for dried chilies, garlic cloves, lemon juice, dried mint and toasted spices. This version is based on a recipe from "A Mediterranean Feast" by Clifford Wright.
Remove the stems and seeds from 8 dried guajillo chilies and 8 dried New Mexico chilies. Immerse the chilies in hot water for 20 minutes. Meanwhile, gently fry 1/2 teaspoon of caraway seeds and 1/4 teaspoon each of coriander seeds and cumin seeds in a skillet to bring out their aromas. Combine the spices with 1 teaspoon of dried mint, and finely grind the mixture.
Place the soaked chilies, ground spices and mint inside a food processor. Add 1/2 tablespoon of kosher salt, 5 cloves of garlic, 3 tablespoons of extra-virgin olive oil and the juice from 1 lemon. Thoroughly blend the ingredients to form a smooth sauce. Place the harissa inside a sterilized glass jar, and cover it with 1/2 inch of extra-virgin olive oil. Keep the harissa in the refrigerator for up to three weeks.
The quick harissa sauce recipe from Food & Wine is also worth considering. Combine 1 mashed clove of garlic with 1 tablespoon of tomato paste and 1 teaspoon of lemon juice. Whisk in 1 tablespoon each of chili powder and smoked paprika, and 1/4 teaspoon each of ground cayenne, ground cumin and ground caraway seeds. Incorporate 6 tablespoons of extra-virgin olive oil, and add salt to taste. Store this harissa in the refrigerator for up to one week.