First, heat 2 tbsps of oil in a large non-stick frying pan over a medium heat. Add the garlic and, stirring regularly, fry for 1–2 minutes until golden and fragrant.
Take care not to burn the garlic or it will become overly bitter. Transfer the garlic to a small bowl and set aside.
Next, increase the heat to high and add 1 tbsp more oil. Add the mushrooms and cook for 4 minutes, or until browning and catching at the edges. Stir in the rosemary, fry for 1–2 minutes until crisp and fragrant.
Stir in the lentils, lemon juice, salt and spinach until wilted. Add a few splashes of water if the pan contents look a bit dry.
Heat 1 tbsp of oil in another non-stick frying pan over a high heat. Crack in the eggs and fry for 1–2 minutes until crisp on the base but still with a runny yolk, or to your liking.
To assemble: divide the mushroomy-lentils between two plates. Top with a fried egg and the reserved crispy garlic. Sprinkle over the Parmesan and the zest of the remaining lemon half.