Vegetarian Lentil and Vegetable Casserole Recipe
Introduction
This hearty vegetarian casserole is packed with tender vegetables, fragrant herbs, and protein-rich lentils. It’s a comforting and nutritious dish that comes together with simple pantry staples, perfect for cozy dinners any night of the week.

Ingredients
- 1 tbsp olive or rapeseed oil
- 1 onion, finely chopped
- 3 garlic cloves, sliced
- 1 tsp smoked paprika
- ½ tsp cumin
- 1 tbsp dried thyme
- 3 medium carrots, sliced (about 200g)
- 2 medium sticks celery, finely sliced (about 120g)
- 1 red pepper, chopped
- 1 yellow pepper, chopped
- 2 x 400g tins tomatoes or peeled cherry tomatoes
- 250ml vegetable stock (1 Knorr vegetable stock pot recommended)
- 2 courgettes, sliced thickly (about 300g)
- 2 sprigs fresh thyme
- 250g cooked lentils (ready-to-eat Puy lentils suggested)
Instructions
- Step 1: Heat the oil in a large, heavy-based pan over medium heat. Add the chopped onion and cook gently for 5 to 10 minutes until softened but not browned.
- Step 2: Stir in the sliced garlic, smoked paprika, cumin, dried thyme, sliced carrots, celery, and chopped peppers. Cook for 5 minutes, stirring occasionally to combine the flavors.
- Step 3: Add the tins of tomatoes, vegetable stock, thickly sliced courgettes, and fresh thyme sprigs. Bring the mixture to a simmer and cook gently for 20 to 25 minutes, until the vegetables are tender.
- Step 4: Remove and discard the fresh thyme sprigs. Stir in the cooked lentils and return the casserole to a gentle simmer to heat through, about 2 to 3 minutes.
- Step 5: Serve the casserole hot, accompanied by wild or white basmati rice, mashed potatoes, or quinoa for a complete meal.
Tips & Variations
- This casserole tastes even better when made the day before, allowing the flavors to deepen and meld together.
- For added texture, sprinkle toasted nuts or seeds on top before serving.
- You can substitute the lentils with chickpeas or black beans for a different protein source.
Storage
Store any leftover casserole in an airtight container in the refrigerator for up to 3 days. Reheat gently on the stove or in the microwave until piping hot, adding a splash of water if it seems too thick.
How to Serve

Serve this delicious recipe with your favorite sides.
FAQs
Can I use fresh tomatoes instead of canned?
Yes, fresh, ripe tomatoes can be used but you may need to cook the casserole a little longer to allow the tomatoes to break down and create a rich sauce.
Is this dish suitable for freezing?
Absolutely. Allow the casserole to cool completely before transferring to a freezer-safe container. It can be frozen for up to 3 months and reheated thoroughly when needed.
Print
Vegetarian Lentil and Vegetable Casserole Recipe
- Total Time: 45 minutes
- Yield: 4 servings 1x
- Diet: Vegetarian
Description
This hearty Vegetarian Casserole is a flavorful and nutritious dish packed with a variety of vegetables, lentils, and aromatic herbs and spices. Slow-simmered to perfection, it brings out deep, rich flavors making it an ideal meal for any day. Best prepared a day ahead, the casserole allows the flavors to meld beautifully, creating a comforting and satisfying vegetarian option.
Ingredients
Vegetables and Aromatics
- 1 tbsp olive or rapeseed oil
- 1 onion, finely chopped
- 3 garlic cloves, sliced
- 3 medium carrots, sliced (about 200g)
- 2 medium sticks celery, finely sliced (about 120g)
- 1 red pepper, chopped
- 1 yellow pepper, chopped
- 2 courgettes, sliced thickly (about 300g)
- 2 sprigs fresh thyme
Spices and Herbs
- 1 tsp smoked paprika
- ½ tsp cumin
- 1 tbsp dried thyme
Liquids and Legumes
- 2 x 400g tins tomatoes or peeled cherry tomatoes
- 250ml vegetable stock cube (1 Knorr vegetable stock pot)
- 250g cooked lentils (e.g., Merchant Gourmet ready-to-eat Puy lentils)
Instructions
- Heat the Oil and Sauté Onions: In a large, heavy-based pan, warm the olive or rapeseed oil over medium heat. Add the finely chopped onion and cook gently for 5 to 10 minutes until the onions are soft and translucent, bringing out their natural sweetness.
- Add Garlic, Spices, and Vegetables: Stir in the sliced garlic, smoked paprika, cumin, and dried thyme. Add the sliced carrots, finely sliced celery, and chopped red and yellow peppers. Cook the mixture for about 5 minutes, allowing the spices to release their aroma and the vegetables to begin softening.
- Add Tomatoes, Stock, Courgettes, and Fresh Thyme: Pour in the tins of tomatoes and the 250ml of vegetable stock. Add the thickly sliced courgettes and sprigs of fresh thyme. Bring the casserole to a simmer and cook gently for 20 to 25 minutes, letting the flavors meld and the vegetables become tender.
- Finish with Lentils and Serve: Remove the sprigs of fresh thyme and stir in the cooked lentils. Bring the casserole back to a gentle simmer to heat through the lentils thoroughly. Serve hot alongside wild and white basmati rice, mashed potatoes, or quinoa for a wholesome meal.
Notes
- For optimal flavor, prepare the casserole a day in advance to allow the ingredients to blend and deepen in taste.
- Use Puy lentils or any cooked green or brown lentils for best texture and flavor.
- This casserole pairs wonderfully with rice, mashed potatoes, or quinoa, providing flexibility to cater to different preferences.
- Can be stored in the refrigerator for up to 3 days or frozen for up to 1 month.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Casserole
- Method: Stovetop
- Cuisine: Vegetarian British
Keywords: vegetarian casserole, lentil casserole, easy vegetarian dinner, stovetop casserole, healthy vegetarian meal

