Indian Chicken and lentils with Rice

This recipe is from A Year of Slow Cooking. we were not overly crazy about this dish, it lacked something, maybe more spice?

2 cups lentils
3 cups chicken broth
3 cups water
1 small yellow onion, diced
1 cup diced celery
1 teaspoon cumin
1/2 teaspoon corriander
1 teaspoon kosher salt
1/2 teaspoon dried mustard
1/2 teaspoon turmeric
4 cloves garlic, chopped
1 (4 ounce) can diced chiles (hot or mild, your choice)--no need to drain
1 tablespoon dried parsley (or 1/4 cup finely chopped fresh)
4 large chicken breast halves

The Directions.

Rinse the lentils under cold water until it runs clear. Dump into the slow cooker. Add broth and water. Add diced onion and celery. Add all spices, the garlic, and chiles. Stir to combine.

Lay 4 chicken breast halves on top of the assembled food.
Cover and cook on low for about 7 hours, or on high for about 4. Before serving, remove chicken from the slow cooker, chop it up, and stir back in. Serve over basmati rice with corn tortillas.