In a medium saucepan, melt the butter over medium heat.

Add the minced garlic and sauté for about 1-2 minutes until it becomes fragrant, but not browned.

Sprinkle the all-purpose flour into the pan, stirring constantly to create a roux. Cook for about 1-2 minutes to remove the raw flour taste.

Gradually pour in the broth (or water), whisking continuously to avoid lumps. This will help create a smooth base for the sauce.

Add the heavy cream and continue to whisk until the mixture is well combined.

Add the freshly chopped dill, Dijon mustard, salt, pepper, allspice berries, bay leaves, juniper berries, and nutmeg.

Stir everything together and bring the sauce to a gentle simmer.

Reduce the heat to low, allowing the sauce to simmer for about 10-15 minutes, stirring occasionally. This will give the flavors time to meld and the sauce to thicken.

Once the sauce has thickened to your desired consistency, remove the bay leaves, allspice berries, and juniper berries.

Stir in the lemon juice, adjusting to taste, to add a bright, tangy finish to the sauce.