Answer: STIR FRY
Each of the groups of pictures clues a marine creature of some sort via a rebus. Each of the descriptions clues a person associated with one of those animals. The descriptions are in alphabetical order by title. The pictures are ordered by answer extraction. Indexing by the number of stars after each picture into the name of the person gives the method of preparation you were told to guess, and the answer to the puzzle.
Here are the animal types, in the order in which they appear in the puzzle and the answer:
SEAL (1) (SEARCH - ARCH + AL)
TROUT (8) (TROJAN - JAN + UT)
WHALE (6) (WHEAT ALE - EAT)
COD (3) (COT + IED - TIE)
DOLPHIN (8) (DOLLAR + SPHINX - LARS - X)
TURTLE (6) (TURKEY + NESTLE - KEYNES)
SHARK (4) (SHALE + ORK - LEO, where ORK is the Order of Random Knights hacking group.)
Here are the mappings of descriptions to pictures, ordered by how the main courses appear in the puzzle:
The FBI Informant is SAM AXE from Burn Notice. The main character, Michael, Sam's best friend, is a spy who was "burned" (cut off from all covert agencies) and dumped in Miami. Michael eats a ton of yogurt, and Sam likes mojitos. Sam is described in the opening credits as "An old friend who used to inform on you to the FBI." Sam is a former US Navy SEAL, one of the main course animals. Indexing gives an S.
The Knight is from the fantasy series "A Song of Ice and Fire" and its television adaptation, "A Game of Thrones." The sigil of House Tully is the TROUT. Younger brother to the leader of House Tully, BRYNDEN TULLY made a name for himself in the War of the Ninepenny Kings (the dish costs nine cents), then had a falling out with his brother. That caused him to fly his own flag in place of his brother's, which was otherwise similar except that the fish on the flag is black instead of white (which is why this dish is blackened). He also left his brother's service to work for his niece and her husband, where he guards the Bloody Gate. Shortly beyond the gate is a place where food is placed in baskets and brought up the side of the mountain to reach his niece's castle. Turnips are mentioned being hauled up several times in the book. The words "river" and "run" appear next to one another in the puzzle, in reference to the fact that he grew up in and rules the castle Riverrun for a while. Indexing gives a T.
The Trader is BRUNO IKSIL, "The London WHALE," who was responsible for a massive loss at JP Morgan's London office on some credit default swap trading. Indexing gives an I.
The Midwife is MIRIAM from "Children of Men." In a dystopian future where humanity has lost the ability to breed and everyone is slowly aging toward death, Britain is doing comparatively well. This results in tons of immigrants trying to get into the country. Miriam is a member of a pro-immigrant group considered a terrorist organization by the British government. The group is known as the "Fishes," and they call Miriam a COD - an English fish. Indexing gives an R.
The Receiver is PAUL WARFIELD, of the Miami DOLPHINS. Before a Super Bowl, Richard Nixon spoke to coach Don Shula and suggested he run a passing play to Warfield. He was born in Ohio in 1960 and inducted into the Hall of Fame (which is also in Ohio) in 1983. Indexing gives an F.
The Artist? The Teenage Mutant Ninja TURTLEs really like pizza and got their powers from some kind of strange ooze in the New York sewers, so you're looking for one of them. Which one? The one named after the artist who painted The Last Supper, LEONARDO. Indexing gives an R.
The Boss references Philadelphia, with the cheesesteak and the description of a Philadelphia roll. One of the most iconic Rocky scenes is when Sylvester Stallone pounds huge slabs of beef in the meat locker. Rocky makes a big deal about taking place in Philadelphia. Rocky's boss is TONY GAZZO, a loan SHARK. Indexing gives a Y.
These letters spell the answer, STIR FRY.