Cut or shred the fennel into thin slices. Chop the chilli and garlic.
Heat 1 Tbsp of oil in a pan then gently sauté the fennel under cover for 10 minutes over low heat.
Add the mushrooms (torn into small pieces, if they’re bigger than bite-size), the chopped chilli & garlic and stir for 5 minutes.
Add the vinegar a soy sauce. Cook for approx. 5 minutes (under cover), until the vegetables are soft.
Add the spinach, stir, then put the lid on and steam over low heat for a couple of minutes until the spinach has wilted.
Stir in the sesame seeds, season to taste and serve.