Black against Nimzo Larsen

What is the best way to play against Nimzo Larsen as black? Also, sometimes this guy I play against also double fianchettos. Something like

Thanks Bacon. Is the idea to give up the e pawn to play d4 after the exchange?

In the 2006 book, Beating Unusual Chess Openings,

https://web.archive.org/web/20140627072813/http://www.chesscafe.com/text/hansen107.pdf

IM Richard Palliser suggested 1 Nf3 d5 2 b3 Bg4.

"An accurate reply, popular amongst grandmasters, which prevents White from smoothly continuing his development with Bb2 and e3. Black intends to capture on f3, before setting up a solid formation, usually with ...e6 and ...g6."

This is one of the games that was mentioned:

https://www.chessgames.com/perl/chessgame?gid=1017742

https://www.chessgames.com/perl/chessgame?gid=1886932

As possible reactions to 1 Nf3 d5 2 b3, GM Paul van der Sterren (2009) gave 2...c5 and 2...Nf6. As reactions to 2...Nf6 3 Bb2, he referred to 3...c5, 3...e6, 3...g6, 3...Bf5, and 3...Bg4.

Base on my short research, the best way to play against the NLA is 1. Nf3 d5 2. b3 Bg4 intending 3... BxNf3. Credit belongs to @kindaspongey

I wasn't very convinced by your main line, but when checked 7...Qxf6 is good for black. Don't think much wrong with OP's line either.

https://www.365chess.com/game.php?gid=3833251

And what is the point of this obscure game? To point out 1 Nf3 d5 2 g3 Bg4 ?

What if

Would it be correct to play Bf5 and then follow with f6 e5 against Bb2?

What is the best way to proceed if d4 instead

IM Palliser suggested 3...Bf5 as a reaction to 3 Ne5 and commented that Black "is threatening ...f6". He suggested 4...Nd7 as a reaction to 1 Nf3 d5 2 b3 Bg4 3 Ne5 Bf5 4 d4.

i think perhaps the most troublesome formation for black to try vs 1.b3 are those which black goes for d5-c5 nf6 g6 structures, especially if black can avoid any line where white swaps bishop for knight to damage your pawn structure on f6. 

its hard to see even the slighest of advantages in those lines, since white loses a lot of the position leverages that make b3 appetizing. 1. you delay early nc6 to avoid the bb5 pin 2. you always have the option to play e6 so you dont have much chance of creating an d isolani 3. the kingside finachetto contests yours, and unlike your flank, black will defend his once castled. 4. black always has the potential threat of d5-d4 so white cant stall for too long. 

but timing  and order are crucial in such lines. White is always threatening ways to funky up the position so this is easier said than done.

All set-ups for Black against 1 b3 are fine. Pick one you like the look of and check the theory for any potential issues with it. Personally I like to build centres as Black and so play 1...e5 2 Bb2 Nc6 3 e3 d5 4 Bb5 Bd6 – which means I need to know how to react to White's attempts to attack it with, variously, 5 f4, 5 c4 and 5 Nf3. If that seems like too much effort... just play something else.

THE Nimzo Larsen begins 1.Nf3 followed by 2.b3. 1.b3 is LArsens penning  and very unsound.

Since I answer 1.Nf3 with 1...Nc6, I am very happy if White insists on playing 2 b3 there.

"[1 b3, 1 b4 and 1 f4] have interesting unique connotations and can even be recommended as an occasional weapon for White. Although the main lines (1 e4, 1 d4 and 1 c4) remain the real McCoys …" - GM Gabor Kallai (1997)

2. d4 and it's a Queen pawn opening with your black knight blocking your c-pawn which sometimes is not a good thing.