1. In a large bowl, soak chickpeas in water overnight. You'll want to cover them by at least a few inches as they will absorb a lot of the water.
2. After they have soaked, drain them and rinse several times. Remove any skins.
3. Put the soaked chickpeas in a pot on the stove. Pour water in to cover the chickpeas by an inch or two. Bring to a boil, and then reduce the heat to a simmer, skimming any foam that rises to the top while cooking. They should be tender after simmering for about 1 1/2 hours. Drain any water that remains in the pot and set aside to cool.
4. Mix the chickpeas, vegetables, and parsley together in a large bowl. Squeeze the lemon juice and olive oil over the rest of the ingredients and mix well.
5. Starting with 1 teaspoon, mix in the harissa. Taste and add 1 teaspoon or more to taste. Yours might be spicier than mine, so make sure you don't add too much. Harissa is a little salty, so I didn't add additional salt; you may want to sprinkle with a little of your favorite course sea salt, though.