Sauté Onion: In a skillet, heat the oil and butter. Add finely chopped onion and cook until golden.
3.5 tablespoons butter, 2 tablespoons extra virgin olive oil, 1 onion
Prepare Giblets: Clean the giblets by removing any bile. Coarsely chop them with the chicken testicles.
1.1 lbs chicken livers and testicles
Cook Giblets: Dust the giblet mixture with flour. Add to the skillet with onion, sage, salt, and pepper. Cook over medium heat for 10 minutes, moistening with chicken broth as needed.
Fresh sage, Flour, Salt, Pepper, Chicken broth
Make Sauce: Whisk together egg yolks and lemon juice. Add to the giblets in the skillet.
2 egg yolks, Juice of half a lemon
Finalize Dish: Turn off the heat, let the dish rest briefly, then serve warm, preferably over toasted Tuscan bread slices, then add some finely chopped parsley or dill.