In a small bowl, combine 2 teaspoons ground cumin, 1 teaspoon ground coriander, 1 teaspoon garam masala, 1/2 teaspoon turmeric powder, 1/4 teaspoon cayenne pepper, and 1 teaspoon salt. Mix thoroughly to blend the dry spices evenly.

Add 1 pound boneless, skinless chicken breast pieces to a medium bowl. Pour in 1/2 cup plain yogurt and 1 tablespoon fresh lemon juice. Sprinkle the prepared spice blend over the chicken and yogurt mixture. Stir until all pieces are completely coated. Let marinate for 5 minutes.

Place a large skillet or cast iron pan over medium-high heat. Add 2 tablespoons vegetable or coconut oil. Heat until the oil shimmers and moves freely in the pan, approximately 2 minutes.

Add 1 large thinly sliced yellow onion to the hot oil. Cook for 3 minutes, stirring occasionally, until the onion becomes translucent and soft.

Add 3 cloves minced garlic and 1 tablespoon grated fresh ginger to the pan. Stir and cook for 1 minute until fragrant.

Add the yogurt-coated chicken and all marinade to the skillet. Cook for 6 to 8 minutes over medium-high heat, stirring frequently, until the chicken is cooked through and no longer pink inside. The sauce will be creamy and lightly coat the chicken.

Taste a piece of chicken once cooked. Adjust seasoning with additional salt, lemon juice, or cayenne pepper if desired.

Warm 8 flour or corn tortillas by wrapping them in a damp paper towel and microwaving for 30 seconds, or by placing them directly over a gas flame for 10 seconds per side. Warm tortillas should be pliable without cracking.

Lay a warm tortilla on a flat surface and spoon a portion of the spiced chicken mixture down the center. Top with 1 cup shredded lettuce or cabbage, 1/2 cup diced fresh tomatoes, 1/4 cup chopped fresh cilantro, 1/2 cup diced cucumber, and 1/4 cup sliced red onion.

Drizzle with tamarind chutney or mint chutney. Squeeze lime wedges over the assembled tacos to add brightness. Serve immediately.