Making this Lentil and Vegetable Stew is a straightforward process, perfect for weeknight dinners or weekend meal prepping. Follow these simple steps to create a flavorful and satisfying stew:

1. Prepare the Vegetables: Begin by thoroughly washing and chopping all your vegetables. Dice the onions, carrots, celery, potatoes, and sweet potato into roughly uniform pieces. Mince the garlic. If using fresh spinach, wash it thoroughly. If using frozen spinach, there’s no need to thaw it beforehand. Having all your vegetables prepped and ready to go will make the cooking process much smoother and more efficient. This step is crucial for ensuring even cooking and consistent textures throughout the stew.
2. Sauté the Aromatics: Place a large pot or Dutch oven over medium heat. Add the olive oil and let it heat up for a moment. Once the oil is shimmering, add the diced onions and sauté for about 5-7 minutes, stirring occasionally, until they become softened and translucent. Sautéing the onions first releases their sweetness and mellows their pungent flavor, creating a flavorful base for the stew. Next, add the minced garlic and sauté for another minute until fragrant. Be careful not to burn the garlic, as it can become bitter. Sautéing the garlic briefly enhances its aroma and flavor without making it overpowering.
3. Add the Vegetables and Spices: Introduce the diced carrots and celery to the pot. Cook for another 5-7 minutes, stirring occasionally, allowing them to soften slightly. This step helps to build layers of flavor and ensures that the heartier vegetables start cooking before the lentils and liquid are added. Next, add the dried thyme and red pepper flakes (if using). Stir to combine and cook for about 30 seconds, until fragrant. Blooming the spices in the warm oil releases their essential oils, intensifying their flavor and infusing the vegetables with aromatic depth.
4. Incorporate Lentils, Tomatoes, and Potatoes: Add the lentils, diced tomatoes (with their juice), diced potatoes, and diced sweet potato to the pot. Stir everything together to ensure the lentils and vegetables are well combined with the aromatics and spices. The tomatoes will release their juices and start to create a saucy base. The potatoes and sweet potatoes will begin to soften as they cook with the other ingredients.
5. Pour in the Vegetable Broth and Bay Leaf: Pour in the vegetable broth, ensuring it covers all the ingredients. Add the bay leaf to the pot. Bring the mixture to a boil, then reduce the heat to low, cover the pot, and let the stew simmer gently. Simmering allows the flavors to meld together beautifully and the lentils and vegetables to cook through completely. The bay leaf will infuse its subtle aroma and flavor into the stew as it simmers.
6. Simmer Until Lentils are Tender: Let the stew simmer for approximately 30-40 minutes, or until the lentils are tender and cooked through. Stir occasionally to prevent sticking to the bottom of the pot. The exact cooking time may vary slightly depending on the type of lentils used and your stove’s heat. You can check the lentils for doneness by tasting a few – they should be soft but not mushy. The vegetables should also be tender but still hold their shape.
7. Stir in Spinach (and Lemon Juice): Once the lentils are cooked, stir in the spinach. If using fresh spinach, add it in handfuls and stir until it wilts down into the stew. If using frozen spinach, add it directly to the pot and stir until it thaws and heats through. The spinach will add a vibrant color and a boost of nutrients to the stew. If using, stir in the fresh lemon juice for a final touch of brightness and acidity. This step is optional but highly recommended as it elevates the overall flavor profile of the stew.
8. Season and Serve: Remove the bay leaf from the stew. Taste the stew and season with salt and black pepper to your preference. Start with a pinch of each and adjust as needed. Remember that flavors will continue to develop as the stew sits. Once seasoned to your liking, the Lentil and Vegetable Stew is ready to serve. Ladle generous portions into bowls and enjoy the comforting warmth and delicious flavors.