Preheat oven to 350 degrees Fahrenheit.

Bring a kettle of water to a boil.

Butter a 2-quart souffle dish or six 1-cup ramekins and place in a baking pan.

Fill the baking pan with enough water to come halfway up the sides of the mold or ramekins.

Beat the eggs in a large bowl.

Stir in the chopped spinach, thyme, minced garlic (optional), cooked millet, grated Gruyere cheese, and milk.

Season with salt and pepper to taste.

Scrape the mixture into the prepared molds, filling them a little more than halfway full.

Pour boiling water into the baking pan to reach halfway up the sides of the molds.

Bake for 5 minutes at 350 degrees Fahrenheit, then reduce the heat to 325 degrees Fahrenheit.

Bake small molds for approximately 40 minutes or until set and a skewer inserted in the center comes out almost clean.

Large timbales will take between 1 to 1.5 hours to bake.

Ensure the water bath does not boil during baking.

Remove the timbales from the oven and let them sit for 10 minutes.

Heat the marinara sauce while the timbales rest.

Spoon 3-4 tablespoons of marinara sauce onto each plate for individual timbales.

Run a knife around the edges of the ramekins and unmold onto the plates.

For a large timbale, unmold onto a platter and cut into wedges to serve.