Preheat oven to 375°F and grease a 9x13-inch baking dish lightly with oil or cooking spray.

In a medium saucepan, combine brown lentils and vegetable broth. Simmer until tender, about 20–25 minutes; drain any excess liquid.

Heat oil in a skillet over medium heat. Add onion and garlic; cook until translucent and fragrant, about 3 minutes.

Stir in grated carrots and diced red bell pepper, cooking 2 more minutes until vibrant and slightly softened.

In a large bowl, toss cooked lentils, sautéed veggies, parsley, thyme, and grated Parmesan to evenly distribute flavors.

Whisk eggs in a small bowl and stir into the lentil mixture to help it set during baking.

Spread half the zucchini slices in the dish, layer lentil mixture, then top with remaining zucchini.

Sprinkle breadcrumbs and a final pinch of cheese over the surface for a crispy, golden crust.

Place in the oven and bake at 375°F for 25–30 minutes, until bubbly and golden brown on top.

Remove the bake and let it rest 10 minutes to set before slicing and serving warm.