In a small bowl, mix oyster sauce with water. Set aside.

In a wok, heat olive oil over medium heat.

Add garlic and onions. Cook until onions are translucent in colour.

Add tomatoes and cook until tomatoes are softened.

Add shrimps and cook until shrimps turn light pink in colour.

Add sayote and oyster sauce-water mixture. 

Bring to a boil.

Lower heat, cover and continue to cook for 15 minutes. Check if sayote is tender.

Season with salt & pepper.

Serve and enjoy!