In a medium bowl, whisk together honey, whole grain mustard, extra virgin olive oil, juice from two lemons, chopped cilantro, minced garlic, yellow curry powder, salt, black pepper, and crushed red pepper flakes until smooth.

Place chicken thighs into a resealable plastic bag or shallow dish, pour the majority of the marinade over, seal or cover, and marinate in the refrigerator for at least 30 minutes up to 4 hours.

Preheat grill to medium-low (about 350°F or 175°C). Remove chicken from marinade, let excess drip off, and grill for about 4 minutes per side, brushing with reserved marinade until internal temperature reaches 165°F.

In a large bowl, combine chopped cucumbers, diced peaches, chopped cilantro, and fresh mint. Drizzle with remaining marinade and a squeeze of fresh lemon juice. Toss and let marinate at room temperature for about 10 minutes.

Arrange the grilled chicken on a platter, top with peach salad, garnish with extra cilantro and mint, and serve.