Caramelized Onion Cream Soup with potatoes

2 tablespoons unsalted butter 4 large onions , peeled and chopped 2 garlic cloves , chopped 1 cup white wine 2 tablespoons sherry wine 4 cups chicken stock,[...]

8 medium flour tortillas 3/4 cup red onion , cut in half and thinly sliced 1/4 lb monterey jack cheese , grated 8 -10 small red potatoes, washed 6 tablespoons[...]