Is western omelette with ham cheese onions and green peppers a homogeneous or heterogeneous mixture?

Heterogeneous mixture.

A homogeneous mixture is a mixture in which the composition is uniform throughout. A heterogeneous mixture is a mixture in which the composition is not uniform throughout. In the case of the western omelette, the ham, cheese, onions, and green peppers are all solid ingredients that are not evenly distributed throughout the egg mixture. Therefore, the western omelette is a heterogeneous mixture.