Spicy Chicken Salad with Tahini Dressing

1 1/2 pounds boneless, skinless chicken thighs or breasts, cut into large chunks
1/4 cup olive oil + 1 tablespoon
Juice of 1 lemon
2 teaspoons cumin
2 teaspoons chili powder
1/2 teaspoon allspice
1/8 teaspoon cayenne
salt 
Tahini Dressing
1/2 cup tahini  
1/4 cup water
1 clove garlic, chopped
1 tablespoon olive oil
2 tablespoons fresh lemon juice, or more to taste
1/4 teaspoon salt, or more to taste
Salad
4 cups chopped romaine lettuce or baby greens
2 roma tomatoes, sliced
1 cucumber, peeled, sliced
2 green onions, sliced
1 red pepper, sliced
chopped cilantro, for garnish

1. Whisk together the 1/4 cup olive oil, lemon juice, spices and salt in a bowl. Place chicken in bowl, turn to coat chicken thoroughly, and marinate for at least 30 minutes in the refrigerator. An hour would be even better.
2. Make the dressing while the meat is marinating: place all ingredients in a blender and blend until smooth. Add more lemon juice or salt, as needed, to taste.
3. Heat remaining 1 tablespoon olive oil in a large skillet over medium heat. Add the chicken and cook, turning once, until cooked through, about 5 minutes per side. Discard the marinade.
4. Slice the chicken pieces and serve with the lettuce and veggies and drizzle the dressing over all. This will serve 4 people.