Into a heavy pot or dutch oven heat the oil. Add the chopped onions and fennel seed and saute until the onions are translucent. Season with salt and pepper.
Add about 1 teaspoon of chopped cilantro.
Add the curry paste, minced garlic, ginger root, turmeric, and cinnamon. Cook this over medium high heat for 2 minutes to let the flavors combine.
Add the chopped tomato into the seasoning mixture and place the lid tightly on the pot. Continue to cook on medium-high heat for 3-4 minutes until the tomatoes begin to break down and form the sauce.
While the sauce is cooking, remove the skin from the chicken breasts, and cut each piece into chunks. I usually cut them crosswise into three large pieces, then cut each piece again, through the middle. If you don't have a knife sharp enough to do this, ask your butcher to help you out with this step.
Add the chicken pieces and stir well, making sure the chicken is evenly coated with the sauce. Squeeze the lemon juice on the top. Turn the temperature to medium low and simmer covered for 20 minutes.
After 20 minutes add the drained lentil soup, and two medium potatoes peeled and cut into chunks. Season this layer with salt and pepper.
Replace the lid, and continue to cook on medium low for another 35 minutes until the chicken is done and the potatoes are fork tender.
Sprinkle with chopped cilantro and serve over Basmati rice.