In these two videos, Matt discusses 1.d4 d5 2.e3 Bf5, preventing White's Stonewall setup by beating White to the d3-h7 diagonal. The only way White can play for an advantage is to play 3.c4 with the goal of an early attack on b7. Some of these positions can also be reached via the Slav Defense.
He also covers the trap line 1.d4 d5 2.e3 Bf5 3.c4 e6 4.Qb3 Nc6! Taking the b7 pawn is a forced draw. Instead he recommends Yaacov Norowitz's 5.Bd2, resulting in a quiet game with a small White edge.