Slow Cooker Beef Roast with Mushrooms & Onions 🥩🍄🧅 This Slow Cooker Beef Roast with Mushrooms & Onions is the ultimate comfort meal! Juicy, tender roast beef cooked low and slow in a rich, savory mushroom gravy that melts in your mouth. Perfect for cozy dinners or Sunday family meals! Ingredients: 3–4 lb beef chuck roast 2 tbsp olive oil 1 large onion, quartered 8 oz baby mushrooms, halved 4 garlic cloves, minced 1 cup beef broth 1 cup red wine (optional; can replace with more broth) 2 tbsp t