Spinach with Chilli and Fermented Tofu

Name: Spinach with Chilli and Fermented Tofu (Jiao Si Fu Ru Chao Bo Cai 椒絲腐乳炒菠菜)
Cuisine: Chinese
Ingredients: 2 tsp finely chopped garlic; Salt (optional); 2 cubes of white fermented tofu; ½ fresh chilli (to taste); 325 g bunched spinach; ¼ tsp caster sugar; 3 tbsp cooking oil