In a large Dutch oven, pour in the chicken stock and add the fresh sage. Bring to a gentle simmer over medium heat for about 10 minutes.

Remove the skins from the garlic and halve each clove, discarding any bitter shoots. Boil in water for 3-4 minutes until slightly tender, then mash and add to the stock.

For the mayonnaise, place the egg yolk, Dijon mustard, and salt into a jar. Slowly drizzle in olive oil while blending until thick and emulsified.

Optional: Strain the broth through a fine mesh sieve for a smoother texture, discarding the solids.

Temper the mayonnaise by adding a small amount of hot soup to it, stirring quickly before integrating it back into the pot.

Ladle the soup into bowls and garnish with croutons, olive oil, smoked paprika, and parsley.