Slow-Cooker Tuscan Pot Roast Recipe

• 1/3 cup olive oil
• 1 2 1/2- to 3-pound bottom-round pot roast
• 2 large onions, quartered
• 2 celery stalks, thinly sliced (2 cups)
• 2 large carrots, thinly sliced (2 cups)
• 3 garlic cloves, minced
• 1 6-ounce can tomato paste
• 1 cup dry red wine
• 1 1/2-ounce package dried mushrooms (such as portobello)
• 1 tablespoon kosher salt
• 1 teaspoon dried oregano
• 1 28-ounce can whole plum tomatoes, chopped, liquid reserved

Directions