Algerian dersa is a spicy garlic and chilli paste, similar to harissa, made by blending garlic, chilli, cumin and paprika together using a mortar and pestle. It is used a lot in the Maghreb region as a seasoning for fish, meat or potatoes. Not everyone uses exactly the same proportions or the same spices. Some people add lemon juice, others add parsley. In short, there are as many variations as there are tastes, but the basic ingredients are almost always the same: garlic, cumin, chilli or cayenne pepper and olive oil.
This was delicious! The 1/2 of a small red chile pepper is vague. I didn't know what kind of red chile but it turns out all I could find fresh that was red was a jalapeno. Because jalapeno's are typically mild in the heat department for us, I used the entire pepper and also left the seeds in. So while I'm not sure I made this as intended, it still came out excellent! - 04 Nov 2017 (Review from Allrecipes USA and Canada)