Preheat oven to 180 degrees Celsius.
Prepare the fennel by trimming the root and removing the top stems. Stand the bulb up and cut it into slices approx 1 cm thick. Coat with olive oil and season with sea salt and pepper. Arrange the slices evenly, without overlapping, in a baking tray. Roast for 15 - 20 minutes, and then turn for a further 15 - 20 minutes until they have evenly browned.
While the fennel is cooking, wash and trim the English spinach and leave to dry. In a small frying pan dry roast the almond slivers over a medium heat until they have browned slightly taking care not to burn them.
Remove the fennel from the oven. Toss through the English spinach to wilt. Squeeze the lemon halves over the vegetables and top with the roasted almonds.
Note: Fennel is delicious sliced very thinly and tossed through a green salad. It's said to be very good for digestive disorders. Fennel seeds can also help relieve flatulence.