Begin by marinating the chicken. In a bowl, mix the yogurt with cumin, paprika, garam masala, and lemon juice. Add the chicken thighs to the marinade, making sure each piece is coated evenly. Allow the chicken to marinate for several hours or overnight for the best flavor infusion.

Next, heat some vegetable oil in a skillet over medium heat. Add the marinated chicken and cook until it turns white all over. Set the cooked chicken aside.

Now, let's prepare the sauce. In the same skillet, sauté the onions, garlic, and ginger until they become translucent and fragrant. Add in the tomato puree and chicken stock, stirring well to combine. Allow the sauce to simmer for a few minutes to develop its flavors.

Add the cooked chicken back into the skillet with the sauce. Simmer the chicken in the sauce for an additional 10-15 minutes, allowing it to soak up the flavors. The sauce will thicken slightly during this time.

Once the chicken is cooked through and the sauce has reached a desirable consistency, your butter chicken is ready to be served. Garnish with some toasted almonds for an extra crunch and visual appeal. This authentic butter chicken dish is best enjoyed with steamed rice or naan bread.