Brown the chopped garlic, onion and parsley in a pan with oil and butter, add the bouquet garni and finally the tuna fish, previously drained and crumbled. Allow the sauce to gain for a few minutes, then season with salt and pepper, and add the capers. Turn the heat down and, after a few minutes, pour in the cream, stir, if necessary add a little flour to thicken the sauce and boil for 5-10 minutes longer. Drain the rice when "al dente”, pour it still hot in a salad bowl and dress it with the sauce, blending in a small knob of butter. Serve with a garnish of slices of hard-boiled egg.