Sanitize all work areas, cutting boards, equipment and sinks used in the preparation of this recipe.
Heat oil in a heavy bottom sauce pot or rondeau over medium heat.
Add leeks in an even layer.
Cook until softened and golden brown.
Add milk.
Simmer until it thickens, about 2-3 minutes.
Remove from the heat. Cool slightly.
Carefully transfer cooled mixture to a cambro (for use with an immersion blender) or into a vitamix blender.
Blend, while constantly attended, until thoroughly combined and smooth.
Add butter & salt.
Continue blending until fully incorporated and smooth. Taste and adjust seasoning as needed.
Cool completely.
Transfer to clean food storage containers. Contact wrap the surface of the Soubise. Cover, label, date and store refrigerated.
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