Almost. Actually the phrase comes from a poem by Virgil in which a Roman peasant spends hundreds of intense lines of Latin describing how he makes his breakfast salad out of the garlic and herbs he has gathered that morning.
The relevant part of the poem goes like this:
The right hand first mashes the fragrant garlic with a pestle,Then grinds everything equally in a juicy mixture.The hand then goes in circles: gradually the separate essencesLose distinction, the color is out of many, one.Neither all green, since milky-white bits resist it,Nor shining milky white, since the herbs are so various.[Virgil: "Moretum." lines 101-106]
There you have the famous American political philosophy, more commonly known as the melting pot. Gather all the immigrants who make up that great land, crush them with a pestle to extract the unique flavors of their divergent background, stir and heat them in the great melting pot, and they will all come out as that fine-tasting soup known as Americans. This is a vision of multi-culturalism.
In Canada we have a different vision. No melting pot here. Nothing gets crushed with a pestle. Every person from every diverse background gets to maintain their own distinct ethnic identity. All the different food groups sit comfortably and colorfully next to one another on the same plate. This is a vision of pluralism - the focus is on the many rather than the one that they might become.
The Canadian vision is seen in the many ethnic groups who happily live in the land of Canada without necessarily thinking of themselves as Canadians (in fact, not too sure what a Canadian really is). It is highlighted in Quebec where, to pursue the culinary image, they love to have their cake (retain their own identity) and eat it too (enjoy the privileges of the Canada at large that many of them want to protect their Francophone culture from).
Either way, the people groups belong to the Lord. Whether he enjoys them in the melting pot of stew that he finds in the USA, or on the plate full of tiny tastes of deliciously distinct flavors that is offered to him in Canada, they are for him. And one day, when all the nations are gathered before him, the culture of the Kingdom will emerge with all the tang and zest of the people groups for him to savor forever.
I'm not sure that the pestle will be there to crush ingredients into an eternal stew. But neither will we all stay in our own food groups in ethnic isolation on the platter of the new earth. Then truly, out of the many, one. The cry will go up to the Lamb: "E pluribus unum". And it will taste wonderful.