In the meantime, use your fingers and a big spoon to scoop out the insides of your halved globe zucchinis and/or bell peppers.
Over medium heat, sautée garlic and onion with a dash of olive oil for a few minutes. Add red pepper and sautée for a few more minutes. I feel that this step brings out the flavor in those ingredients, but you could skip it if you're short on time.
Preheat the oven to 350 degrees and grease a baking sheet or large casserole dish.