Eating fish, even sparingly, does make you a pescatarian, not vegetarian. Just an FYI. I also want to let you know that things like flax seed and chia seed have significantly higher concentrations of omega-3 (one serving of flax oil has 3x the amount of omega-3's as one serving of fish oil...plus it has omega-6 and omega-9 and no cholesterol or saturated fat. One serving of chia seed has 20x the amount of omega-3's as one serving of fish. If you are looking for DHA specifically, cut out the "middle fish" and consume the algae where the fish get their DHA).
Anyway, your body can be confused with tastes. I don't know why you'd be craving meat (I don't and haven't since I went from omni to vegan), but when you do, just cook yourself up a portabello mushroom cap and treat it like you would a burger. Here's a recipe I made for vegan chili burgers:
CHILI
15oz tomatoes with diced jalapenos
15oz beans seasoned for chili
1 small can fire roasted green chilies
1 small can sliced black olives, drained
1/2 cup cubed polenta
1/2 packet of your favorite taco seasoning
Combine and heat through.
BURGER
1 large portabello mushroom cap, cleaned
Dab of olive oil
Garlic powder
Red pepper flake (optional)
Bun
Hummus
Spring mix salad
Green olives stuffed with garlic
Drizzle oil on both sides of mushroom cap, season with garlic and red pepper. Cook until warm (I had to use a nuker, as I was at work at the time).
Spread both sides of the bun with hummus and top with halved olives and the spring mix. Add mushroom and the heated chili, and enjoy.
Of course, you can add whatever you'd like to you burger. :)
Here's a picture of the finished product: http://img.photobucket.com/albums/v391/strawberryp0cky/recipes/ChiliBurger2.jpg
You can always hit it with some BBQ sauce and/or steak seasoning, too. Portabellos are meaty mushrooms to boot.