Preheat the oven to 350°F. Place the nuts on a small, rimmed baking sheet and toast, stirring once or twice, until deep golden, about 8 minutes.
In a small saucepan, combine the chicken stock, raisins, if using, and saffron, over low heat; let steep while you make the chicken.
Season the chicken liberally with salt and pepper.
In a large skillet, heat the olive oil, four turns of the pan, over medium-high. Working in batches if necessary, cook the chicken, turning once, until browned on both sides, 8-10 minutes per batch; transfer to a plate. Add the onion and garlic to the skillet; season. Cook, stirring occasionally, until the onion softens, about 4 minutes. Stir in the flour. Add the sherry and bring to a simmer. Add the olives, orange juice and zest, and saffron stock. Slide the chicken and any juices back into the skillet. Simmer until the chicken is cooked through, 5-7 minutes more.
Serve the chicken in shallow bowls topped with the herbs and almonds. Serve with the bread alongside for mopping.