Slow Cooker Ratatouille

Name: Slow Cooker Ratatouille
Ingredients: 1 large eggplant or two smaller ones, peeled and cut into 1-inch cubes; 3 medium zucchini quartered lengthwise and sliced into 1/2 inch pieces; 1 Tablespoon Kosher salt; 4 medium tomatoes chopped; 1 medium red onion diced; 2 large sweet bell peppers chopped (I prefer orange and yellow for color, but use what you like); 6 garlic cloves minced; 1 container .67 oz chopped fresh basil, or about 1/3 cup loosely packed; 1 6 oz can tomato paste; 1 Tablespoon Herbs de Provence; 1 teaspoon pepper; Parmesan cheese optional for garnish