Begin by heating the olive oil and butter in a large pot over medium heat.
Add the chopped onion and cook until it becomes translucent and soft, which should take about 5 minutes.

Introduce the garlic cloves to the pot and sauté them for another 2-3 minutes, making sure they don’t burn.
Pour the broth into the pot and toss in the thyme and bay leaves. Elevate the heat to bring the mixture to a boil, then lower the heat to maintain a gentle simmer for 30 minutes, or until the garlic is tender and aromatic.
After the soup has simmered, discard the thyme and bay leaves, and season with salt and pepper to your liking.
In a separate bowl, whisk together the egg yolks and Parmesan cheese.
Carefully whisk a scoop of hot soup into the egg mixture to temper it, then gradually mix the tempered egg mixture back into the pot of soup.
Continue to simmer the soup for an additional 5 minutes, stirring constantly, until the soup has thickened slightly.
Serve the soup hot, accompanied by slices of crusty bread and garnished with chopped parsley if using.

Prep Time: 10 minutes | Total Time: 45 minutes | Servings: 4