Cook the mushrooms and spinach. Heat 1 teaspoon of the olive oil in a non-stick frying pan over a medium heat. Add the mushrooms and cook for 3–4 minutes until softened and lightly golden. Add the baby spinach and cook for another minute until just wilted. Transfer to a plate and leave to cool slightly.
Prepare the egg mixture. Crack the eggs into a mixing bowl and add the ground coriander, cumin, turmeric and a generous pinch of salt and black pepper. Whisk until the yolks and whites are completely combined.
Add the vegetables. Fold the onion, garlic, tomato, green chilli and fresh coriander through the egg mixture. Add the cooked mushrooms and spinach, followed by the grated cheese, and gently mix until everything is evenly distributed.
Cook the first omelette. Wipe out the frying pan if needed and add a small drizzle of olive oil. Heat over a medium heat, then pour in half of the egg mixture. Use a spatula to gently spread the ingredients towards the edges of the pan.
Cook for around 3 minutes, until the underside is golden and the top is mostly set. Carefully flip the omelette and cook for a further 1–2 minutes, until the egg is cooked through and the cheese has melted. Slide onto a serving plate.
Repeat with the remaining egg mixture and a little more olive oil to make the second omelette.
Serve warm, with a little extra fresh coriander or sliced green chilli if you like.