For this dish, we use yogurt as the base for a unique tang. You can also use full-fat coconut milk for a creamier curry.
Prepare the pickled onion: Combine 2 Tbsp sugar, 1 Tbsp salt, peppercorns and vinegar in a small sauce pot. Bring to a boil; then remove from heat and add sliced onions and garlic clove, making sure they are fully submerged. Let cool to room temperature. Use the onions immediately or transfer to a sealable glass jar and keep in the fridge for up to 3 weeks.
Cut chicken into 1’’ cubes and add to a medium bowl with curry powder, a pinch of salt and pepper. Toss to coat.
Heat 2 Tbsp. coconut oil in a large high-top skillet over medium-high. Add diced onion and minced garlic and cook, stirring until softened, about 2 minutes.
Add chicken to the skillet and continue to sauté for another 3 minutes until chicken begins to brown. In a small bowl, whisk together yogurt, ginger and ½ tsp salt. Add yogurt mixture to skillet and cook, tossing occasionally, until chicken is cooked through, about 5 minutes. Fold spinach into mixture and cook another minute, until spinach is wilted.
Serve hot with chopped cilantro and pickled onions.