Heat the oil in a large tagine over medium low heat. Add the onion & garlic and cook until soft. Stir in the spices & cook until fragrant.
Turn the heat onto low & gently pour in 2 cups of broth. Next add in add the tomato paste, herbs, & all vegetables except for the garnishments & stir. Cover with the lid & cook for 45 minutes.
Check the vegetables to make sure they are tender, if not cook for additional 15 minutes, adding another 1/2 cup of broth or water if needed. Once tender, stir in the lemon juice & top with the green onions.