Preheat your oven to 190°C (375°F). Rinse and dry the bell peppers, then slice off the tops and carefully scoop out the seeds and membranes, leaving the stems intact for a rustic look.
Bring a large pot of water to a boil, then gently submerge the peppers and let them simmer for about 5 minutes until slightly softened. Carefully lift them out and drain well—this helps them soften further during baking.
In a mixing bowl, combine your leftover grains, drained beans, corn, chopped herbs, smoked paprika, and a splash of olive oil. Season with salt and pepper, then stir until everything is evenly mixed and fragrant.
Using a spoon or scoop, generously stuff each pepper with the grain mixture, pressing lightly to pack the filling in and ensure it stays in place during baking.
Arrange the stuffed peppers upright in a baking dish. If desired, sprinkle the tops with vegan cheese or breadcrumbs for a crispy finishing touch. Drizzle a little olive oil over the peppers for extra shine and flavor.
Bake the peppers in the preheated oven for 25 to 30 minutes, until they are tender and slightly blistered, and the filling is heated through. The peppers should be soft but hold their shape, with a nice charred skin for added flavor.
Remove the peppers from the oven and let them rest for about 5 minutes. This allows the filling to settle and makes them easier to serve.
Serve the stuffed peppers warm, drizzled with a squeeze of lemon or a drizzle of olive oil for extra brightness. Enjoy their tender, smoky, and hearty flavors!