A Southern (USA) word for the supplemental food, dishes, ingredients, and accompaniments to whatever you are eating, cooking, or serving.
A hamburger can have fixins (tomatoes, pickles, ketchup), barbecued meat can have fixins (baked beans, cole slaw, potato salad), and even fixins can have fixins (baked beans made with added bacon, toppings for a baked potato).
For Thanksgiving dinner we had turkey with all the fixins--cranberry sauce, green beans, wild rice, sweet potatoes.
I'll have the fajita burrito with all the fixins like grilled onions, green peppers, sour cream, cheese.
What fixins would you like with your burger, hon?
I like all the fixins with my Chinese food--wonton soup, egg roll, lots of rice with the dish, and a fortune cookie at the end.