Cut chicken breasts into 1/2" x 1" chunks. Place in glass bowl and set aside.

In a hot dry cast iron skillet, dry roast the cumin and coriander seeds for 30-60 seconds. Do not burn. Remove roasted seeds from skillet.

Open cardamom pods and remove the black seeds. Discard the woody pods. Add toasted cumin and coriander seeds and other spices to a spice or coffee grinder and grind to a fine powder.

Sprinkle all the powdered spices over the chicken pieces and mix well with a spoon. Be sure all the chicken pieces are coated with the spice mixture. Cover and place in refrigerator to marinate for at least two hours and better, over night.

Place 1 tablespoon of olive oil in tava, wok or large sauté pan. Heat oil and add chopped onions. Sauté until translucent. Add garlic and sauté another 30 seconds. Remove onions and garlic from pan and set aside.

Remove chicken from refrigerator and add some more oil to the pan and sauté the chicken pieces a few at a time until browned. Set the browned chicken aside and sauté more until all the chicken has been browned. Do not overheat the pan as this will burn the spices stuck to the pan. If the spices on the bottom of the pan are burned, then wash the pan.

Return the chicken to the pan and add the sautéed onions and garlic.

Add chicken broth to pan.

Mix ingredients well, deglazing the browned spices off the bottom of pan.

Simmer chicken uncovered until liquid is reduced by half, about 45 minutes.

Add drained tomato chunks.

Continue to simmer another 5 minutes or so. The liquid should be reduced so that it is the thickness of gravy.

Mix the sour cream and the plain yogurt together well.

Remove the pan from the heat and stir in the sour cream-yogurt mixture.

Serve immediately over plain basmati rice.

cause the sauce to break or curdle when it is added to the hot curry if the yogurt is not mixed with sour cream. Non-fat yogurt is even worse. If you must use low or non-fat ingredients, you will just have to live with a curdled sauce.