The phrase "consistency of heavy cream" means that something has a texture that is thick, smooth, and creamy, similar to how heavy cream looks and feels. Full definition
Allow to stand in fridge for 1 hour until consistency of heavy cream. (drizzledwithflavor.com)
Slowly stir in the chicken broth, stirring constantly, until the liquid is the consistency of heavy cream. (irunforwine.net)
Stir the contents of the bowl into the garlic broth and whisk it continuously over low - medium heat until it thickens to about the consistency of heavy cream or a loose bechamel. (soupaddict.com)