Learn English – What do you call a word that’s been used unusually (not according to definition)

"I'm literally going to fit him for cement shoes."

This would mean more than simply "I intend to kill him." It would mean "I intend to encase his feet in cement and throw him in the river [or lake, or ocean, etc.], thereby killing him".

That said, the sort of person who would actually kill someone in this way — who would speak those words in a literal sense — is someone who is not too worried about violating convention and would very likely not be fussy about speech and grammar; he might easily mean "literal" in its corrupted "figurative" sense.

EDIT

I see from the comments that some people insist on carrying any expression of literalness out to six decimal places; in other words, that for a thing to be described as being "literally" some state or condition, the state or condition must be exact to that amount. Or more.

I disagree.

The act of "fitting someone for cement shoes" (or overshoes, or boots) refers to a very specific way of killing someone. It is a figurative description, but one which describes a real action: putting someone's feet in a tub of cement, letting it harden, and then hurling the poor unfortunate to his death by drowning. To that extent, I insist that someone could be "literally fitted for cement overshoes" if they were killed in the manner that the trope suggests. The expression does not cover murder by gunfire, garotte, stiletto, or poison, but it does cover that particular case. Literally.

Let's look at another case:

I'm going to literally beat you to a pulp.

Now, the literal-minded may insist that the word "literally" may not be used there, because "to a pulp" is a figure of speech. But if they do, they first have to explain exactly what degree of beating qualifies or doesn't qualify as producing pulp. A mashed nose or smashed ear or other severe deformation may be construed as a "pulping," and if one allows that at some point pulp is produced then the argument becomes trivial and pedantic and not worth the trouble. The objection is reduced to the state of an advertising claim for orange juice: no pulp, some pulp, lots of pulp.

I believe that if someone threatens to "literally beat me to a pulp" I face severe damage to my person. Whether or not that qualifies in some minds as "pulp" is irrelevant.

Now, we have to look at this on a scale. The guideline to apply here would involve whether the action or state described as "literal" does contain actual parts of truth ("some pulp") or none at all ("no pulp"). If someone says

It literally made my head explode.

we may poke fun at them by saying their head has made a splendid recovery since them, because they seem to be talking out of it. In that case, the figurative expression (even though it does describe a state of abject bewilderment or consternation) is rendered ridiculous because it is too far from reality to be considered literal in any sense ("no pulp").

To sum up: This is all a matter of degree. Some figurative expressions, if they refer to actual actions or conditions that can be produced, may be modified by some form of the adjective "literal" — even to the literal-minded. (Hey, did we agree on what a mind is yet? Literally?)

This phrase is not common, and appears to just be a diversion into cooking terms to create an analogy.

Sautéing is as you defined it. When you sauté olive oil, garlic, and onion together when starting to make an Italian pasta sauce, the outcome is that the oil will take in the flavor of the garlic and onion.

So, by analogy, Paul Ryan has not taken in the flavor of foreign policy, i.e. he is inexperienced in foreign policy.

Readers will probably understand this analogy if they understand the more commonly used analogy of marinating.