In a Dutch oven, pour in your chicken stock and add fresh sage leaves. Heat over medium until simmering, about 5-7 minutes.

Peel 15-20 garlic cloves, halve them, and set aside.

Boil the halved garlic cloves in water for 3-4 minutes until tender. Drain and set aside.

Mash the boiled garlic finely with a fork or potato masher.

Add the mashed garlic to the simmering stock and stir well, simmering for an additional 10 minutes.

Prepare homemade mayonnaise by combining egg yolk, Dijon mustard, and salt in a jar. Slowly drizzle in olive oil while blending until thickened.

Optional: Strain the soup through a fine mesh sieve for a silky texture.

Temper the mayonnaise by whisking in a cup of hot soup. Stir this mixture back into the pot.

Reheat the soup gently over low heat for 5-7 minutes.

Ladle soup into bowls, garnish with croutons and a drizzle of olive oil, and serve.