1 medium tree tomato
2 teaspoons cornstarch
1 cup water
2/3 3/4 cups tomato puree
1 cup sliced red onion
3 cloves garlic, minced
3 medium potatoes, peeled and cubed
1 cup sliced peppers
1 tablespoon vegetable oil
7 tablespoons dry white wine
1 tablespoon vinegar
1/2 teaspoon salt