Place butter and oil in 2-quart pan over medium heat. When butter is melted, add onion and garlic; cook until onion is tender. Add rice; cook, stirring constantly, 3 minutes or until rice looks milky and opaque. Add salt, oregano, cumin, turmeric and broth. Bring to a boil. Cover, reduce heat and simmer 20 to 25 minutes or until rice is tender and all liquid is absorbed. Peel and pit avocado; dice. Fluff up rice with fork; add avocado and toss gently. Turn off heat; let stand 5 minutes before serving.