In an 8 qt. sauce pan or pot over medium-high heat, heat 1 ½ teaspoons of the oil. Add half the beef and cook, turning occasionally, until browned on all sides, about 5 minutes. Transfer to a plate. Heat another 1 ½ teaspoons oil and brown remaining beef cubes. Add to already browned beef. Add remaining 1 tablespoon oil to pan and stir in the onion, celery, carrots, garlic, parsnip, mushrooms and thyme. Cook, stirring occasionally, until vegetables start to soften, about 6 to 7 minutes.