Heat oil in a large pan over medium-high heat. Add onion and cook, stirring for 3 minutes. Add garlic, cardamom, lemon juice and zest and cook 30 seconds. Add spinach, lemon juice and zest. Cook, stirring, until spinach is wilted, about 30 seconds.
Add cooked barley, feta, almonds and raisins. Season with salt and pepper to taste. Heat through if serving warm drizzle with the juice of one lemon and chopped fresh parsley.
For a great salad option: store in an air-tight container in fridge and serve cold, drizzled with more fresh lemon juice.