Preheat your oven to 400°F (200°C). Slice the top off a head of garlic and place it cut-side up on a baking tray. Drizzle it generously with olive oil, then cover it with aluminum foil. Roast for 30–40 minutes, until the garlic is soft and golden brown.

In a large pot, pour in your chicken stock and bring it to a gentle boil over medium-high heat. Add a few sprigs of dried sage and a pinch of salt. Once boiling, reduce the heat to low and let it simmer for about 10 minutes.

Once your roasted garlic is cool enough to handle, squeeze the cloves out of their skins into a bowl and mash it into a smooth paste.

In a bowl, whisk together the egg yolks and Dijon mustard. Gradually drizzle in olive oil while whisking to create a creamy emulsion.

Slowly whisk in the mashed garlic and emulsion into the stock until everything is combined. Serve with toasted baguette slices.