Bring a large pot of salted water to a boil and cook the brown rice penne according to package directions until al dente.
While the pasta cooks, dice the chicken breast into bite-sized pieces and season with sea salt, black pepper, and dried oregano.
Heat the olive oil in a large skillet over medium-high heat. Add the chicken and sauté for 5-7 minutes until golden brown and cooked through.
Reduce the heat to medium and add the minced garlic, sautéing for 1 minute until fragrant.
Add the baby spinach to the skillet and toss until just wilted, then remove the pan from the heat.
In a small bowl, whisk together the Greek yogurt, parmesan cheese, and chicken broth until smooth.
Drain the pasta, reserving a splash of pasta water, and add the pasta to the skillet with the chicken.
Pour the yogurt mixture over the pasta and chicken, tossing gently to coat. If the sauce is too thick, add a tablespoon of reserved pasta water until the desired velvety consistency is reached.
Serve immediately while warm.