Preheat your oven to 190°C (375°F). Place the halved peppers in a baking dish, standing upright, ready to be stuffed.
Heat oil in a pan over medium heat until it shimmers and starts to smell fragrant. Add the finely chopped onion and sauté for about 5 minutes until translucent and soft.
Add minced garlic, cumin, paprika, and chili powder to the onions. Stir well and cook for another minute until the spices are fragrant.
Stir in the cooked lentils and chopped tomatoes, mixing everything together. Let it simmer gently for 5 minutes until heated through and slightly thickened.
Remove the filling from heat and stir in half of the shredded cheese and a squeeze of lemon juice for brightness.
Use a spoon to carefully fill each pepper with the lentil mixture, pressing gently to pack the filling in.
Top each stuffed pepper with the remaining shredded cheese, spreading it evenly over the top.
Bake in the preheated oven for 25-30 minutes, until the peppers are tender and the cheese is bubbly and golden brown.
Remove from the oven and let rest for 5 minutes to settle the flavors and make serving easier.
Squeeze a little more lemon juice over the peppers for a fresh zing, then serve hot, enjoying the colorful and hearty dish.
