Bison and Red Wine Shepherd's Pie

Whisk first 4 ingredients in large bowl. Add bison; toss. Heat large pot over medium heat. Add bacon; cook until crisp. Transfer to paper towels. Add 2 tablespoons oil to pot; increase heat to medium-high. Working in batches, cook bison until browned, adding more oil by tablespoonfuls as needed. Return to same bowl. Add chopped onion, carrot, celery, and garlic to pot; cover and cook until vegetables soften, stirring occasionally, about 5 minutes. Add wine; bring to boil, scraping up any browned bits. Add broth, tomatoes, bay leaves, thyme, sage, reserved bacon, and bison. Reduce heat to low. Cover; simmer until bison is tender, stirring occasionally, about 2 hours (beef may take 1 1/2 hours). Meanwhile, cook pearl onions in large saucepan of boiling salted water 2 minutes. Transfer to bowl of ice water; trim and peel. Transfer bison to rimmed baking sheet. Cut meat off bones; cut meat into 3/4-inch cubes. Add parsnips and turnips to pot with bison sauce. Simmer until tender, stirring occasionally, 10 to 15 minutes. Add pearl onions; cook 5 minutes. Return meat to pot. Season with salt and pepper.