This is the 1355th most frequent Russian word.
белорусской
The Russian word "белорусской" means "Belarusian" (feminine form, genitive or dative case).
In this sentence, 'белорусской' is used as an adjective in the dative case, modifying 'кухне' to describe the relation to Belarus.
Белорусской кухне характерны сытные блюда.
Belarusian cuisine is characterized by hearty dishes.
Here, 'белорусской' is an adjective in the dative case, modifying 'культурой', indicating admiration towards Belarusian culture.
Мы восхищаемся белорусской культурой и традициями.
We admire Belarusian culture and traditions.
In this example, 'белорусской' is an adjective in the genitive case, modifying 'истории' to specify that the history is related to Belarus.