Bring a pot of salted water to a boil and cook the brown rice pasta according to package directions until al dente.
While the pasta cooks, season the chicken breast with sea salt, black pepper, and garlic powder.
Heat olive oil in a large skillet over medium heat and sear the chicken until golden brown and cooked through, about 5-6 minutes per side.
Remove the chicken from the pan, let it rest for 2 minutes, then slice it into thin strips.
In the same skillet, add the minced garlic and sauté for 30 seconds until fragrant, then stir in the baby spinach until wilted.
Lower the heat to low and whisk in the Greek yogurt, parmesan cheese, and lemon juice until a smooth, creamy sauce forms.
Toss the cooked pasta and sliced chicken into the sauce, adding a splash of pasta water if needed to reach your desired consistency, and serve immediately.