Put verbena, sugar, and 3⁄4 cup water into a small saucepan and boil over medium-high heat, undisturbed, until syrup is slightly thickened, about 5 minutes. Strain syrup into a medium bowl, discarding solids. Stir lemon juice and zest into syrup and set aside to let cool. Add strawberries, cover, and let berries macerate in a cool spot for 2–4 hours.
Drain berries, reserving syrup. Purée half the berries and half the syrup together in a blender. Transfer to a small saucepan and cook over medium heat, stirring constantly, until sauce has reduced by half, about 10 minutes. Set sauce aside to let cool.
Whisk cream in a large bowl until soft peaks form. Add crème fraîche and 1 tbsp. of the reserved syrup (save remaining syrup for another use) and whisk until medium-stiff peaks form. Fold in half the berry sauce.
Set aside 4 strawberry slices, then divide remaining berries and sauce among four chilled 4-oz. parfait glasses. Fill glasses with strawberry cream and garnish each with a strawberry.