Tangy Swiss Chard Side

2 tablespoons butter
2 tablespoons olive oil
1 tablespoon minced garlic
1/2 small red (or white) onion (or scallions) diced
1 bunch Swiss chard, stems and center ribs cut out and chopped together, leaves coarsely chopped separately
1/4 to 1/2 cup dry white wine (or dash or two of vinegar)  
1 tablespoon fresh lemon juice
2 tablespoons freshly grated Parmesan cheese
salt to taste (optional)

PREPARATION
Melt butter and olive oil together in a large skillet over medium-high heat.
Stir in the garlic and onion, and cook for 30 seconds until fragrant.
Add the chard stems and the white wine (or dash of vinegar).
Simmer until the stems begin to soften, about 5 minutes.
Stir in the chard leaves, and cook until wilted.
Finally, stir in lemon juice and Parmesan cheese; season to taste with salt.