Take the chicken out of the fridge. It benefits from not being fridge-cold when placed on a hot pan as the meat would otherwise release a lot of liquid and cause it to boil rather than fry.
Put the rice in a pot and rinse it thoroughly with cold water. The water doesn't need to be completely clear, but you want to rinse out most of the "excess" starch.
Fill the pot with fresh, cold water so that the rice is covered with about 2 centimeters of water.
Cook the rice until tender on the stove. You can advantageously use a rice cooker, but a regular pot/saucepan is also fine. Set the finished rice aside and now start preparing all the ingredients for the wok. Everything needs to be prepped beforehand as there won't be much time to do it once we start cooking.
Cut the green beans into pieces of 3 centimeters in length.
Cut the tomatoes into thick wedges.
Cut the spring onions into thin slices.
Rinse the baby spinach and basil leaves.
Cut the baby corn into 2 centimeter pieces.
Peel the onion and cut it into thick wedges.
Cut half of the chilies into thin, diagonal slices. It looks decorative in the finished dish.
Roughly chop the remaining half of the chilies and place them in a mortar. You can also use a mini-chopper if you don't have a mortar. Cut the garlic into smaller slices and place them in the mortar as well.
Give it a good grind in the mortar. It should become a fairly coarse mixture.
Cut the chicken breasts into suitable pieces. I like to cut them into diagonal slices and possibly halve them if some pieces become too long. However, long, diagonal slices of chicken also look very decorative!
Place your wok on the stove and turn the heat up to high. When the wok is hot, add the oil.
Turn on the extractor fan and add the coarse chili/garlic mixture to the hot oil. Let it take on some color.
Now add the meat to the pan and let it quickly gain some color.
Then add soy sauce, fish sauce, oyster sauce, and sugar.
Stir it well. Add tomatoes, green beans, spring onions, baby corn, red onion, and the thin chili slices.
Let everything simmer for a bit while stirring.
Add baby spinach and basil leaves.
Stir and turn off the heat. Stir a few times while the leaves wilt from the heat. Serve with jasmine rice.