Spinach: can be the main component of a delicious salad. You can boil it or you can eat it raw. I recommend that you eat it raw. Just wash the spinach and make a delicious salad. Spinach is a great source of vitamin A and C, but also of minerals like magnesium and iron. The lack of cholesterol and fats should make it a preferred food.
Lettuce: fresh salad is great. A 100 grams of lettuce has only 12 kcal. Lettuces are full of potassium, calcium, iron, zinc, vitamin C, B1, B2, B5, B6, PP, E, A. A whole lot of reasons not to ever exclude lettuce form your meals.
Green Onion and Green Garlic: both can add an extra flavor for your salads and also extremely healthy. Onion has a rich content of vitamin C, potassium, allicin, being rich in antioxidants.
Green garlic contains vitamin C, carbohydrates, antibiotic substances and minerals. You should especially eat garlic when you are sick. Being a great antiseptic it will help you stay safe form all the viruses that roam today.
Radishes: a delicious breakfast can be made of toast, cheese and fresh radishes. Radishes are low on calories and full of potassium, vitamin C, folic acid and vegetal fibers.
A word of advice: greens get oxidized fast when they get in contact with metal. You should break them up using your hands and put them into your salads. This method is especially possible and recommended for spinach and lettuce.