Mix sesame oil, garlic, bicarbonate of soda and 1 tablespoons rice bran oil in a glass or stainless steel bowl. Add sliced steak and mix to coat evenly. Cover with cling film and refrigerate overnight.
Place noodles in heat-proof bowl and cover with boiling water.
Heat oil in a large wok, add red curry paste and cook until fragrant.
Add garlic, ginger, coriander, lime juice, fish sauce and sugar. Stirring after each addition.
Add coconut milk, water and beef stock stir. Leave to simmer.
In a small frying pan, stir-fry stir-fry vegetables and spring onion for 2 to 3 minutes, then add to the soup.
Reheat small frying pan, adding oil if necessary and pan-sear the steak. Remove from heat and set aside.
In two deep soup bowls, half fill with noodles, then top with steak and beansprouts.
Ladle hot soup into bowls, sprinkle with mint and basil.
Garnish with spring onion and sliced chilli.
Rice bran oil can be purchased in speciality shops or online.