Make the masala paste: In a small bowl, mix together the onion, garlic, ginger, cinnamon, chili powder, turmeric, cumin, lemon juice, and cayenne pepper (if using).
Marinate the chicken: In a separate bowl, combine the chicken with the Greek yogurt and half of the masala paste. Mix well, cover, and refrigerate while preparing the rice.
Cook the rice: Rinse the rice under cold water and drain thoroughly. In a saucepan, cook the rice according to package directions. Once cooked, fluff the rice with a fork and season with salt and pepper to taste.
Cook the chicken: Heat a nonstick pan over medium-high heat. Add the olive oil and brown the marinated chicken pieces on all sides. Remove the chicken from the pan and set aside.
Finish the sauce: In the same pan, add the remaining masala paste and stir for 1 minute. Add tomato paste and the browned chicken. Simmer for 10 minutes, until the chicken is cooked to an internal temperature of 160℉ (71℃). Stir in the heavy cream and season with salt and pepper. Let the sauce simmer until thick and creamy. Add chicken broth gradually if the sauce is too thick.
Toss the cucumber and onion with oil and vinegar. Season with a pinch of salt and pepper to taste.
Make the tea according to the directions on the package. Serve.
Serve the chicken over rice and garnish with chopped cilantro. Serve with cucumber salad, chamomile tea, vanilla ice cream topped with sliced banana.