In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for an additional minute until fragrant.
Add the green beans to the pot and sauté for about 3-4 minutes, stirring occasionally.
Pour in the diced tomatoes with their juice and the vegetable broth. Stir to combine.
Add the ground cumin, ground coriander, paprika, salt, and pepper. Bring the mixture to a boil, then reduce the heat to low.
Cover the pot and let it simmer for about 25-30 minutes, or until the green beans are tender.
Stir in the lemon juice just before serving.
Garnish with fresh parsley and serve warm.