Sausage and Swiss Chard Soup

1 cup dry white wine
2 tablespoons olive oil
1 1/2 lbs andouille chicken sausage
1 small yellow onion, diced
2 celery ribs, diced
1 carrot, peeled and diced
1 leek, white portion only, diced
2 garlic cloves, minced
1 teaspoon fresh thyme, minced
6 cups chicken stock, warmed
1 cup water, warmed
2 cups white beans, cooked and drained (or canned)
4 ounces swiss chard, stems removed, chopped
salt & freshly ground black pepper, to taste
1/4 cup grated parmigiano-reggiano cheese (for garnish) (optional)

In a small saucepan over medium heat, boil the wine until reduced to 1/2 cup, 7 to 10 minutes. Set aside.
In a soup pot over medium heat, warm the olive oil. Add the sausage and cook until browned, about 5 minutes per side. Transfer to a plate and let cool, then cut diagonally into 1/2-inch slices.
In the same pot over medium-low heat, cook the onion, celery, carrot and leek, stirring occasionally, until soft, about 10 minutes. Add the garlic and thyme and cook, stirring occasionally, for 2 minutes more. Add the reduced wine, the stock and water, increase the heat to medium-high and simmer for 15 to 20 minutes. Add the sausage, white beans and chard and cook until the chard wilts, 5 to 8 minutes. Season with salt and pepper.