Lentil Spinach Soup with Lemon

Name: Lentil Spinach Soup with Lemon
Prep time: 5 min
Cook time: 40 min
Total time: 45 min
Cuisine: Middle Eastern
Ingredients: 3 tablespoons olive oil; 1 whole onion, (diced); 1 whole carrot, (peeled and diced); 1 teaspoon minced garlic; 1 tablespoon tomato paste; 1 1/2 teaspoons cumin; 1/4 teaspoon cayenne pepper; 1/2 teaspoon salt; 1/4 teaspoon black pepper; 1 quart low sodium vegetable stock ((if not vegetarian, you can substitute chicken stock)); 1 cup water; 1 1/4 cups brown, green or red lentils, (rinsed and sorted); 1 bay leaf; 2 cups fresh spinach leaves ((or substitute kale, swiss chard, or another favorite green)); 1/4 cup chopped cilantro ((or can substitute parsley-- I prefer the flavor of cilantro here)); 1 whole lemon