Bring the vegetable broth to a boil in a pot, then add the rice, reduce heat to low, cover, and simmer until tender and fluffy, about 15 minutes. Fluff with a fork and set aside.
Preheat your oven to 375°F (190°C). Carefully cut the tops off the bell peppers and remove the seeds and membranes to create a hollow cavity inside each pepper.
Heat olive oil in a skillet over medium heat. Sauté the chopped onion and minced garlic until fragrant and translucent, about 2-3 minutes. Add the diced zucchini and cook until tender, another 3-4 minutes. Season with oregano, salt, and pepper.
In a mixing bowl, combine the cooked rice, sautéed vegetables, crumbled feta cheese, and a pinch of salt and pepper. Mix until evenly incorporated.
Stuff each hollowed-out pepper with the rice and vegetable mixture, pressing lightly to pack the filling in. Place the filled peppers upright in a baking dish.
Cover the baking dish with foil or a lid and bake in the preheated oven for about 25-30 minutes, or until the peppers are tender and slightly blistered on the edges.
Remove the foil and bake for an additional 5 minutes to allow the edges to crisp up slightly and the filling to heat through.
Take the stuffed peppers out of the oven and let them cool slightly. Garnish with fresh herbs if desired, then serve hot and enjoy!
