Harissa traditionally is a very spicy blend and these beans pack a punch. Reduce the Harissa to 2 tsp. for a less intense heat.
In a saucepan, blanch the green beans and carrots. In a separate saucepan blanch the garbanzo beans. The garbanzo beans have a husk that will remove easily after blanching.
For blanching: Bring pot of water with a pinch of salt to a rapid boil. While water heats, fill a large bowl 3/4 full with ice and add enough cold water to just cover ice. Add vegetables to boiling water in small batches to ensure the water does not lose its boil. Boil vegetables for 3 to 4 min., strain them into a colander and submerge colander containing vegetables into ice bath as quickly as possible. Remove from ice bath as soon as vegetables are no longer warm.
In a small bowl, thoroughly mix together Harissa, lemon juice, olive oil and white wine vinegar. Place green beans, carrots, garbanzo beans and cucumbers in a bowl and toss with Harissa dressing.
Serve cold, or warm slightly by reheating in a pan.