This weekend I made lasagne using extra firm tofu in place of the noodles.
It was very good, in fact, I couldn't tell the difference. I made half the
pan with noodles and half with tofu. I had my SO taste the tofu version
without telling him what was different. His comment "Yea, so what's the
different about it?"

Recipe:
1 lb ground beef - browned.
1 Jar Newman's Marinara sauce (6 net carbs per 1/2 cup)
1 lb extra firm tofu sliced thin and (6 lasagne noodles)
1 lb full fat ricotta cheese
8 Oz mozzarella cheese
1 cup shredded parmesan cheese  

Spoon a little sauce in the bottom of the pan (I used a 12" square pan)

1st layer
    tofu/noodles
    layer 1/2 the ground beef mixture
    and 1/2 of the mozzarella cheese
    spoon 1/2 of the remaining sauce over this
2nd layer
    tofu/noodles
    spread ricotta cheese
    1/2 cup parmesan cheese  
    (no sauce on this layer)
3rd layer
    tofu/noodles
    balance of the ground beef mixture
    balance of sauce
    1/2 cup parmesan cheese  

Bake at 350 deg for about 45 min
top with remaining mozzarella cheese and return to oven until cheese is
melted