Preheat the oven to 400 degrees F (200 degrees C), and line a sheet pan with parchment paper or foil.Add asparagus, yellow squash, zucchini, onion, bell pepper, 2 tablespoons olive oil, and 2 tablespoons Cajun seasoning; toss until vegetables are well coated. Stir in cocktail wieners, and spread everything evenly on the prepared pan.
