Stir together salt, pepper, cumin, coriander, paprika, turmeric, cinnamon, and ginger in a small bowl.
Pat chicken dry and coat all over with half of the spice mix.
Heat olive oil in a heavy pot over medium-high. Sear chicken until golden on both sides, 6–8 minutes total. Transfer to a plate.
Drop heat to medium. Cook onion in the pot until softened, about 4 minutes. Stir in garlic and tomato paste; cook 1 minute.
Add rice and the remaining spice mix. Stir to coat and lightly toast the grains, 1 minute.
Pour in broth and add diced tomatoes and raisins. Scrape up browned bits and bring to a gentle boil.
Nestle chicken and any juices into the rice. Cover, reduce heat to low, and simmer until rice is tender, 18–20 minutes.
Remove from heat and let stand, covered, 5 minutes. Fluff the rice.
Fold in lemon juice, lemon zest, and herbs. Sprinkle with toasted almonds and serve warm.