Prep all ingredients as listed above.

Preheat a grill or griddle pan over medium heat.

In a bowl, whisk together the garlic powder, dried oregano, lemon juice, and olive oil to make the marinade. Season with salt and pepper to taste. Set aside half of the marinade for brushing on the buns.

Brush one side of the butterflied chicken breast with the remaining marinade and season with salt and pepper.

Place the chicken on the hot grill, marinated side down. Brush the top with more marinade. Grill for about 6 minutes, then flip, brush again, and grill for another 6 minutes. Cover the grill or pan and cook until the chicken reaches an internal temperature of 165°F (74°C). Let rest for 5 minutes.

Brush the inside of each brioche bun with the reserved marinade and lightly grill or toast until golden brown.

Assemble the sandwiches by spreading mayonnaise on both sides of each bun. Layer butter lettuce, tomato slices, the grilled chicken, Swiss cheese, and red onion.

To make the sparkling chia fresca, combine all the ingredients together. Stir well and let sit for 5 minutes to allow the chia seeds to bloom.

Serve the sandwich with carrots, hummus, blueberries, and the sparkling chia fresca.