1 Tbs cornflour = 2 Tbs flour
1 tsp baking powder = 1/4 tsp baking soda & 1/2 tsp cream of tartar
1 cup sour milk = 1 cup fresh milk with 1 Tbs vinegar or lemon juice stirred in or 1 cup buttermilk
1 cup canned tomatoes = approx 1-1/2 cups cut up fresh tomatoes simmered 10 minutes