Heat oven to 400°F.
Grease cookie sheet or spray with cooking spray.
In medium bowl, stir together Bisquick mix and boiling water; beat vigorously 20 strokes.
On work surface generously sprinkled with Bisquick mix, gently roll dough to coat.
Shape into a ball; knead 10 times.
Roll out dough to ⅛-inch thickness.
Cut with 2-inch round cutter dipped in Bisquick mix.
Place rounds about 2 inches apart on cookie sheet.
In small bowl, mix mayonnaise, Parmesan cheese and onion juice; mix well.
Spread each round with ½ teaspoon mayonnaise mixture.
Top with slightly less than 1 teaspoon artichokes and another ½ teaspoon mayonnaise mixture.
Place 1 tomato slice on each round, and top with 1 teaspoon mayonnaise mixture.
Bake 10 to 12 minutes or until golden brown and puffy.
Garnish with parsley.
Serve warm or at room temperature.