Preheat your oven to 375°F (190°C). Slice the tops off the bell peppers and scoop out the seeds and membranes, creating space for the filling.
Bring vegetable broth to a boil in a small pot. Add the rinsed rice, reduce the heat, cover, and simmer until tender and fluffy, about 15 minutes.
While the rice cooks, heat olive oil in a skillet over medium heat. Add the minced garlic and diced red bell pepper, sautéing until fragrant and the peppers soften, about 3-4 minutes.
Stir in the diced zucchini, smoked paprika, and oregano. Cook for another 2-3 minutes until the vegetables are just tender and fragrant.
Mix in the cooked rice and balsamic vinegar into the skillet, stirring well to combine. Season with salt and pepper to taste. Remove from heat.
Fill each hollowed-out bell pepper with the rice and vegetable mixture, pressing lightly to pack the filling in place.
Top each stuffed pepper with shredded cheese for a melty, golden finish.
Place the filled peppers upright in a baking dish and cover with foil. Bake in the preheated oven for 25-30 minutes until the peppers are tender and the cheese is bubbly.
Remove the foil and bake for an additional 5 minutes to crisp the cheese on top, if desired. The peppers should look vibrant and slightly caramelized at the edges.
Once baked, let the stuffed peppers rest for 5 minutes. Serve warm, garnished with fresh herbs if you like.
