Substitute your meat proteins with other proteins. If you're still eating meat 6x/week I can't imagine that one day will deprive you of much protein if you don't manage to equal the amt of protein you usually eat.
Beans, Eggs, Nuts, Tofu, are all proteins.
All the dishes that people have listed are good....
A larger variety of vegetables than you typically offer is good too. Instead of your main meat dish, make 3 veggie "sides".
And as a former vegetarian, I also consider Mac and Cheese insufficient. Mac and cheese and a big nutty salad, maybe. And I never really used Tofu. There's a baked/smoked tofu I used to make Toasted Tomato-cheese-tofu sandwiches with, but other than that, I didn't really use it.
Roasted vegetable sandwiches is one of my favorite things to make (roast onion slices, eggplant, bell peppers, garlic, zucch/yellowsquash, mushrooms, top with muenster cheese)
Dishes of each Spanish Rice (rice made with Ro-Tel and tomato sauce instead of water), Beans and Corn (can of each, drained and rinsed, heated thru), chopped bell peppers, shredded cheddar, sour cream, salsa, guacamole, tortillas, for Build-Yer-Own Burrito night. It's easy to assemble, stretches for more people, keeps and reheats well.
Make a pot of couscous, and toss in toasted pine nuts, chopped tomatoes, roasted garlic, artichoke hearts, olive oil and italian seasoning (and any other veg you're interested in... chopped broccoli, bell peppers, whatever works with just a few minutes of heating/steam).... is fast and filling.
If you're in Eugene or maybe Portland, you have access to Yumm! sauce. If not, here's a recipe:
http://mpchickchat.blogspot.com/2005/11/recipe-rip-off-edited.html
Make some brown rice, top with black beans, cheddar cheese, sour cream (or strained yogurt) salsa, and FauxYummSauce (which is pretty close to the original, tho I disagree with her comment re yeasts; brewers is essential). The sauce is nutty and full of protein, the beans and rice in the dish are all complex carbs that do good things, and the veggie bits on top are tasty accents. I froze my sauce in an ice cube tray, heated up the bean/rice combo in the morning and packed in a thermal container, brought a sauce cube and my other toppings in separate containers, and assembled it all for lunch for weeks at a time, because it was sooooo tasty.