Mix paprika, cumin, salt, cayenne, cinnamon, turmeric, and black pepper together in a small bowl.

Pat chicken thighs dry and place them in a resealable plastic bag. Sprinkle paprika mixture over chicken thighs; massage the bag to coat chicken evenly.

Heat oil in a tagine over medium heat. Add chicken; cook until browned, 2 to 4 minutes per side. Transfer to a plate. Cook and stir fennel, onion, and garlic in the tagine. Stir in half of the garbanzo beans, chicken broth, 1/2 cup green olives, harissa, 1/2 of the preserved lemon, and ginger.

Lay chicken over garbanzo bean mixture; sprinkle remaining olives on top. Scatter cherry tomatoes on top. Cover and simmer over medium-low heat until chicken is tender, 45 minutes to 1 hour.

Combine remaining garbanzo beans with 2 tablespoons of broth from the tagine in a food processor or blender; blend into a thin paste.

Transfer chicken to a serving dish. Stir garbanzo bean paste into the tagine. Simmer until flavors combine, about 5 minutes. Spoon broth mixture over chicken.

Garnish with remaining preserved lemon and toasted almonds.