For the chicken: Preheat a grill or oven to 450 degrees F. If using a gas grill, set to medium-high heat on one side and low on the other side. If using a charcoal grill, bank hot coals on one side of the grill.
Brush the chicken with the oil and season with the spice mix and a liberal amount of salt and pepper. Put the chicken on the hot side of the grill bone-side down, close the lid and cook for 3 to 4 minutes.
Meanwhile, whisk together the honey, mustard and soy sauce in a small bowl.
Flip the chicken, brush with the glaze and grill for 1 to 2 minutes. Move the chicken to the cool side of the grill bone-side down and apply the remaining glaze. Close the lid, open the vents halfway if using a charcoal grill and continue to cook until the chicken registers 160 degrees F in the thickest part, 15 to 20 minutes longer. If using the oven, place the chicken bone-side down on a baking sheet and roast, brushing with the glaze occasionally, until the chicken registers 160 degrees F in the thickest part, 25 to 30 minutes.
For the spinach salad: In a medium bowl, mix together the spinach, chickpeas and onions in a large bowl; set aside.
Put a heavy-bottomed skillet on the hot side of the grill, add the bacon and cook until crisp.
Add the vinegar, mustard, and honey to an almost-empty ketchup container and shake vigorously (or whisk together the vinegar, mustard, honey and ketchup in a small bowl). Remove the skillet from the heat and mix in the ketchup mixture to make a warm dressing.
Pour the dressing over the greens and toss together. Transfer the greens to a platter and top with the chicken.