Preheat oven to 400°F (200°C).

Melt butter in a pan over medium heat.

Add garlic and shallots to the pan and cook for a few minutes until softened.

Add mushrooms to the pan and season with salt and pepper.

Cook until the water from the mushrooms has evaporated.

Stir in coriander.

In a mixing bowl, combine ground meat, diced tomatoes, and chopped onions.

Add chicken livers, breadcrumbs, nutmeg, egg, parsley, salt, and pepper to the bowl.

Blend all ingredients well until thoroughly combined.

Spoon the meat mixture into a small loaf pan and pat it down firmly.

Place the loaf pan inside a larger pan.

Pour boiling water into the larger pan, surrounding the loaf pan.

Place both pans on the stovetop and bring the water to a boil.

Cover the meat loaf with foil.

Transfer both pans with water to the preheated oven.

Bake for one hour.

Remove the foil cover.

Bake for an additional 15 minutes to brown the top.

Remove from oven and let rest briefly.

Serve hot or cold with cornichon pickles and good mustard.