It's easy to become accustomed to doing things a certain way -- soups are made with chicken broth, gravy is made with beef or poultry stock, chili has ground beef -- that it's easy to go-to the traditional meaty bases of so many dishes. Meat can be an incredible flavoring agent, and certain cuts are definitely worth tasting every now and then if you enjoy them, but replacing everyday meals with vegetarian alternatives can make a huge difference both in your wallet and in your general health. Here's a quick guide to which substitutes work best.
Soy meat substitutes -- This is probably the easiest. There are frozen ground beef substitutes, veggie burgers, and chicken patties available in nearly every grocery store that mimic the real thing so well you might never notice. But they tend to be higher in sodium, so just don't rely on meat substitutes too often.
As for more natural alternatives, tempeh is my personal favorite. It's quite versatile and there are different varieties available, usually various combinations of soy and whole grains. It's a block that's been fermented, so it has a mild nutty flavor and firm texture similar to lean ground beef. Crumble it into a stir fry, grill into patties whole, or cube it and marinate for a kebob, it can fill in with aplomb on most dishes.
Tofu -- Tofu is polarizing. People either love it or hate it, although most have only tried it a few times at best. There are different varieties, the most common are silken and regular tofu. Silken tofu is better for using in smoothies or baked goods and has a slippery feel, while regular tofu is more rough and granular but makes for a much better addition to savory dishes.
Silken tofu is best blended into other things, like aforementioned smoothies. It's often used in place of eggs in baked goods, and can be similarly scrambled like eggs for a breakfast dish.
Regular tofu is more appropriate for stir fries, salads, and other dishes where it's kept in larger pieces. It absorbs marinades and sauce flavors much better than silken tofu and retains its shape more. However, it can be slower to cook. To mimic the Chinese restaurant experience, cut your tofu into pieces the night before and freeze them in a ziploc. Fry the frozen pieces, being careful of any splattering from oil, and you'll have that signature chewy, delicious texture.
Nuts -- These can impart good fats along with protein in many dishes, they can be toasted or added raw. Crushed cashews are fantastic for thickening up sauces and soups, especially curries.
As for being a meat substitute, these are best used either as a topping or well blended with whole grains. They can add new dimensions to everything from casseroles to stir fries, just be careful not to overcook them.
Beans -- Similar to nuts, these are best used as an addition or filler to dishes with other flavorful agents. They're more versatile than nuts because they can be heated on a higher temperature for a longer time, although anything will burn if you really put your mind to it.
Some people prefer to use them whole, others like a refried or crushed version. For dishes like black bean burgers, crushed is best, but in soups, casseroles, or enchiladas, either whole or refried can work. Refried has a deceiving name, but it does not require a lot of extra fat to taste good.
Chickpeas -- These are extremely versatile, being used in batters to pizza crusts to salad toppings. They do well being marinated, pureed into hummus and batter, baked alongside other vegetables and absorbing their flavor, being a high protein topping to a salad, the list goes on. They do contain carbs, as do most things in life, but the fiber and protein of whole chickpeas offsets it in moderation.
Wild Rice -- This is one of my favorite additions to vegetarian soups, because it thickens and adds texture without being intrusive. It's not low carb, but it has enough protein to justify itself in moderate doses. I use it to thicken soups, and it's especially divine in chili. It can also be used with balsamic dressing and/or olive oil with herbs, fresh chopped vegetables, garlic, and brined cheeses like feta to make a portable cold salad. This also applies to whole grains like farro and quinoa.
Polenta -- Also not a member of the non low-carb family, but it's similar to pasta. I like it in breakfast hash in place of potatoes.
Seitan -- This is pure gluten. Yes, evil gluten! It's stretchier and spongier, so this works well sliced into thinner pieces and treated like stewed barbeque, or used in place of steak or shredded chicken and beef in tacos. It can hold onto a lot of flavor, it's best combined with vegetables or other sources of protein due to the texture. However, its ability to absorb sauces and marinades make it more versatile than meets the eye!