Preheat the oven to 400°F (205°C).
Toss the halved red peppers with 1 tablespoon olive oil, the minced garlic, a pinch of kosher salt and pepper, and the oregano in a 9×13-inch baking dish.
Roast the peppers in the preheated oven for 20–25 minutes, until they begin to char and soften.
While the peppers roast, bring a large pot of salted water to a boil and cook the orzo (or quinoa) according to package directions until al dente; drain well.
Place the cooked orzo in a bowl and toss with the balsamic vinegar, kalamata olives, chopped pepperoncini, chopped toasted pine nuts, and crumbled feta; season with salt and pepper to taste.
Make the lemon-basil tomato mixture by combining the halved cherry tomatoes, chopped basil, 1/4 cup olive oil, lemon zest, a pinch of crushed red pepper flakes, and a little kosher salt; stir to combine.
Divide and spoon the warm orzo mixture into the roasted pepper halves.
Drizzle the lemon-basil tomato mixture over the stuffed peppers and serve warm.
