A few people here (particularly some who do a lot of cardio workouts) eat quinoa, which is a psuedo-grain. By and large, though, all beans, grains, and grain-like substances are excluded from the primal blueprint. They're high carb and contain anti-nutrients, contribute to systemic inflammation, etc. So, it's better to avoid them, at least most of the time.
The side-dish thing just takes some getting used to. At first, it's weird not to see a pile of starch on 1/3 of your plate, but before long you'll grow quite accustomed to filling up on extra veggies or other primal foods instead.
Roast some veggies for one side dish, and serve a salad for the other.
Steam some veggies and top them with butter, and serve deviled eggs or an egg salad for your other side.
Put a selection of olives, pickles, and roasted bell peppers on the table alongside a generous pile of veggies.
Occasionally, something like cotttage cheese and berries is nice.
Jicama "chips" are fun to dip in guacamole.
Avocado slices are tasty and filling.
One-dish meals (soups, stews, frittatas, casseroles, chilis, curries, stir frys, etc) don't necessarily require a side.
Heck, NO meal really requires a side. Be creative! Be flexible! Want to serve two different meats? Meat and eggs? Go ahead -- don't let cultural traditions rein you in.