以…为底层的饭菜
a pile of one type of food on which other food is arranged as a meal
roasted vegetables on a bed of rice 底下铺了一层米饭的烤蔬菜
Serve the beef on a bed of polenta with mushrooms and peppers.
Pile the avocados on a bed of lettuce.
You could serve the fish on a bed of lightly cooked greens.
See also: bed noun (BOTTOM)