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For example, if one wishes to drink almond milk while eating meat, he needs to indicate that it is in fact almond milk, not regular milk, which is forbidden. In the olden days, this was done by popping some whole almonds into the milk. Today, this can be achieved by having the container on the table, making it clear that it is almond milk.6
The same would need to be done in order to serve a veggie burger that resembles meat, topped with real cheese, or to serve a beef burger under a slice of imitation cheese. It’s fine to eat, provided that the package is nearby and visible, or its parve identity is spelled out on the menu, receipt, etc.
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