Pierce the sausages with a toothpick in several places.  Quarter the fennel bulbs lengthwise.  Place the sausages and the fennel in a medium saucepan.  Add the wine, fennel seeds, and dried oregano and bring to a boil.  Immediately reduce the heat to low and simmer for 10 minutes.

Remove the sausages and fennel and let them cool.  Slice each sausage on the diagonal into thirds.  Slice portobello mushrooms in half and then into 1-inch slices.

Alternately thread pieces of sausage, fennel and mushrooms onto 4 or 5 skewers.  Cover skewers or transfer to a sealable container and refrigerate until you are ready to grill.

Once your grill is ready, mix olive oil and balsamic vinegar in a small bowl.  Brush skewers with the oil and vinegar mixture.

Grill the kabobs, turning once until the sausages are lightly browned, about 8 to 10 minutes.  

Serve hot with grilled bread and La Chertosa Reserve Chardonnay.