Creamy Lemon-Ricotta Cheesecake

4 tablespoon(s) (1/2 stick) margarine or butter

4 teaspoon(s) grated lemon peel

1 1/4 cup(s) sugar

1/4 cup(s) cornstarch

2 package(s) (8 ounces each) cream cheese , softened

1 container(s) (15 ounces) ricotta cheese

4 large eggs

2 cup(s) half-and-half or light cream

1/3 cup(s) fresh lemon juice

2 teaspoon(s) vanilla extract Lemon-peel strips and mint sprigs for garnish