Spinach with Sesame Sauce

Name: Spinach with Sesame Sauce (Ma Jiang Bo Cai 麻醬菠菜)
Cuisine: Chinese
Ingredients: 4 tbsp runny sesame paste; 1 tsp sesame oil; 1 tbsp cooking oil, plus more if needed; 1 tsp sesame seeds; 2–3 pinches of caster sugar; Salt; 300 g bunched spinach