Roasted Radishes Bathed in Anchovy

Name: Roasted Radishes Bathed in Anchovy
Ingredients: 1 large bunch radishes, trimmed and quartered; butter, for buttering gratin dish; 1 tablespoon fat rendered from bacon or lardons; 1 tablespoon clarified butter (ghee); 1 fat and friendly anchovy, preferably Greek and packed in salt; 2 teaspoons fresh lemon juice; sprinkling AP flour, about a teaspoon; 1/4 teaspoon mustard powder; 1/8 teaspoon pimentón; 2 sprigs thyme; 2 teaspoons creme fraiche, optional