In a wide saucepan, melt the Breton salted butter over medium heat. Once it foams, stir in the lemon juice and sugar cubes. Cook gently until the sugar fully dissolves into a smooth caramel.
Add the carrots, tossing to coat them evenly in the glossy sauce. Season with salt and pepper, partially cover, and simmer for 25 minutes, stirring occasionally. The carrots are ready when they're shiny, tender, and slightly firm at the center.
Finish with a sprinkle of chopped flat-leaf parsley and serve immediately for a sophisticated, restaurant-worthy side.
