Brown the Italian sausage in a large skillet along with the caraway seeds and the garlic.
While the sausage cooks, slice the red pepper and green onions.
After the sausage is cooked, stir in the dried basil and the malt vinegar.
Let simmer on the stovetop, uncovered, for 5 minutes.
While the sausage mixture is simmering, gather four bowls for serving the salad.
Wilt the spinach by placing two cups of spinach in each bowl, and cooking each bowl for one minute. If you decide to cook two bowls together, increase the microwave cooking time to 1 and 1/2 minutes.
When the sausage mixture has simmered for 5 minutes, remove it from the heat.
Top each bowl of wilted spinach with 1/4 of the sausage mixture, then add the red peppers and green onions to each bowl.
Top with sliced, fresh mushrooms, if using.