Savory Bread Pudding

Name: Savory Bread Pudding
Ingredients: 8 ounces (225 grams) thick-cut bacon (about 5 slices), cut into 1/2-inch dice; 1 small onion, diced; 1 bunch Swiss chard, stems thinly sliced and leaves separated, roughly chopped; 6 large eggs; 1 1/2 cups (360 milliliters) heavy cream; 1 1/2 cups (360 ml) chicken stock; 1 teaspoon cayenne pepper; 1/4 teaspoon ground cinnamon; Pinch ground cloves; 1 teaspoon kosher salt; 10 cups (400 grams) 1-inch cubes bread, such as French, sourdough, wheat or rye; 2 cups (8 ounces/225 grams) grated Gruyere cheese; 1/2 cup (50 grams) grated Parmigiano-Reggiano cheese; Unsalted butter, for greasing the pan