Boil chicken thighs in water for 20 minutes or until fully cooked. You can discard the water after or use it as a soup base. Cool down the chicken and shred or cut it. Put aside.
Dice the white part of a leek, carrots, bell pepper. Peel the garlic clove. Trim and cut green beans into 3 or 4 parts.
In your soup pot, heat up olive oil over medium heat. Add whole garlic clove (you can crush it slightly with the flat side of your knife blade), cook until slightly brown. Discard the garlic. Add leeks to the pot and cook for one minutes stirring often. Add carrots and bell pepper and cook for another 2 minutes stirring occasionally.
Pour water or broth into the pot, add better then bouillon base, dry oregano, green beans. Cover and bring it to boil. Simmer for 10 min. Add pasta and cook until it's almost done on medium heat (5-8 minutes).
Turn heat on low, stir in the shredded chicken into the soup, add lemon juice and simmer for few more minutes. Give it a taste and add salt, more lemon juice by taste. Turn if the heat and let it sit covered for 5 min. Enjoy!