This sounds delish... I love salmon and fettuccine alfredo. Gonna give this a try as soon as I get some more eggs and butter. But my take on alfredo is just with butter and parmesan... so this will be my take on it:
Loose the flour and half & half.
Double the butter (or at least one more TB) and divide into 4 chunks.
Place serving plates in 200°F oven.
Undercook the pasta 'till just firmer than al dente, in about half the water you would normally use (say about 2 quarts). Reserve a half cup of the pasta water, drain pasta, and return to pot.
Add pasta water, cheese, and butter and 1/4 teaspoon salt to pot. Set pot over low heat and, using tongs, toss and stir to thoroughly combine, about 1 minute. Remove pot from heat and cover.
In a hot pan, add EVOO and swirl, then salmon. After a minute or two add garlic, and sear 'till color change comes up to about half way. Flip salmon, add a knob of butter, sherry, and a splash of lemon juice or a decent pinch of lemon zest, a dash of cayenne or paprika, some minced parsley, and baste until done.
Toss pasta vigorously once more so sauce thoroughly coats pasta and any cheese clumps are emulsified into sauce, about 30 seconds.
Plate pasta on hot plates and top with salmon in any way you like (I would keep the fillet slices whole, or break it up however you wish).