In grill pan or cast iron skillet, over med/high heat, cook the sausages until cooked through, turning regularly.
When sausage is cooked, add bell peppers and onions, drizzle with olive oil and season with salt & pepper. Grill until tender.
Add garlic to peppers and onions and grill for another 3-4 minutes.
Serve on toasted french roll.
Optional toppings: mustard, grated cheese