Prepare the vegetables. Slice the eggplant and zucchini lengthwise into ½ inch thick slices and slice the peppers lengthwise into quarters.
In a large bowl, combine the olive oil, balsamic vinegar, Italian seasoning or oregano, crushed chillies, and a pinch of salt and pepper.
Add sliced vegetables to the bowl with the olive oil mixture and toss until everything is well coated. If needed, add a touch more olive oil, balsamic vinegar and seasoning to ensure all of the vegetables are well coated.
Heat a grill to medium-high heat, add vegetables to one side of the grill and cook, turning once, until tender; 8-10 minutes for the bell peppers, 5-7 minutes for the zucchini and eggplant.
On the other side of the grill, add sausages and cook for 8-12 minutes until cooked through with an internal temperature of 160°F.
Once cooked, remove the vegetables from the grill and slice them into bite-size pieces, and serve warm with sausages.