Place the cashews on a cookie sheet and roast for 5-10 minutes, or until golden brown (watch carefully).
In a large frying pan heat the oil. Cook onions over medium heat for 2 minutes, or until soft. Add the rice, garlic, and fennel seeds and cook, stirring frequently, for 1-2 minutes or until the rice is evenly coated.
Increase the heat to high. Add the lemon juice, stock and 1 tsp salt. Bring to boil. Reduce heat to low, cover, and cook for 45 minutes without lifting the lid.
Remove from heat and sprinkle with spinach and herbs. Let sit, covered, for about 8 minutes. Using a fork, distribute the spinache and herbs through the rice.