Heat oven to 350°F. In medium bowl, combine flour, pecans and brown sugar; mix well. With pastry blender or fork, cut in margarine until mixture resembles coarse crumbs. Spread in ungreased 15x10x1-inch baking pan. Bake at 350°F. for 15 to 20 minutes or until light golden brown, stirring occasionally. Cool 30 minutes or until completely cooled.
In large bowl, combine condensed milk, lemon juice and orange juice; beat until smooth. Add 2 cups strawberries; beat at low speed until broken up. Fold in whipped cream. In ten 4-oz. parfait glasses, alternate layers of strawberry mixture with crumbs, ending with crumbs. Freeze 2 hours or until firm.
To serve, let stand at room temperature for 15 to 30 minutes. If desired, garnish with additional whipped cream, strawberries and mint leaves.