Mandarin Sweet & Sour Sauce

We just go this recipe from an old friend of my husband's family and immediately fell in love with it. -Brenda

8 cups tomatoes, stems removed, quartered & blended in blender (save out 1 cup)
4 cups onions, peeled & diced
3 cups green pepper, diced
7 cups sugar
3 cups white vinegar
1/2 cup soy sauce
2 - 20 ounce cans crushed pineapple, do not drain
1 cup corn starch

Place all ingredients except 1 cup blended tomatoes and 1 cup cornstarch. Bring to a boil. Reduce heat to a simmer (low boil) and simmer for 19 minutes. In a separate bowl, blend 1 cup tomatoes and 1 cup cornstarch until smooth. Gradually pour cornstarch mixture into sauce whisking vigorously. Stir until thickened, about 3 - 5 minutes. Pour into pint jars leaving 1/4" headspace. Process in waterbath for 45 minutes. Makes about 6 - 7 pints.