Rinse the lentils thoroughly under cold water until the water runs clear and set aside to drain.
Preheat your oven to 180°C (350°F). Chop the onion and carrots into small dice, and mince the garlic.
Heat olive oil in a large skillet over medium heat, then add the chopped onion and carrots. Cook until they soften and become fragrant, about 5 minutes, listening for a gentle sizzle.
Add the minced garlic and tomato paste to the skillet, stirring until the tomato paste darkens slightly and releases a rich aroma, about 2 minutes.
Transfer the sautéed vegetables to a mixing bowl. Add the rinsed lentils, vegetable broth, cumin, smoked paprika, and season with salt and pepper. Stir everything well to combine.
Pour the lentil mixture into the prepared baking dish, spreading evenly. Cover loosely with foil to trap moisture during baking.
Bake for 40 minutes, until the mixture is bubbling and the lentils are tender. Remove the foil for the last 10 minutes to allow the top to crisp and brown slightly.
After baking, sprinkle the shredded cheese evenly over the top and return to the oven uncovered for an additional 10-15 minutes, until the cheese is melted and golden.
Remove from the oven and let it rest for about 10 minutes. This helps the flavors meld and makes serving easier.
Scoop the casserole onto plates and enjoy this hearty, caramelized lentil dish with your favorite sides.