I only do side dishes for guests and parties.

For myself I usually cook one thing - which may be a main or a large side or a soup depending on how much I want and what's on hand - which may be served with rice. In
Asian terms rice or bread is the main dish, anything else is a side.

When I do side dishes, yes, I generally match the ethnicity (or quite close). The exception is general Euro/American dishes where I'll often use an ethnic soup or side that's compatible.