Slow Cooker Beef Stew

Ingredients

• 2 ½ pounds stew meat (see notes)
• ½ teaspoon black pepper
• ½ teaspoon garlic salt
• ½ teaspoon celery salt
• 1/4 cup flour
• 3-6 tablespoons olive oil
• 3 Tablespoons cold butter (separated)
• 2 cups yellow onion (diced)
• 4 cloves garlic (minced)
• 1 cup high-quality cabernet sauvignon (merlot works as well. See notes.)
• 4 cups beef broth
• 2 tsp better than bouillon (or 2 beef bouillon cubes)
• 2 Tablespoons Worcestershire Sauce
• 3 Tablespoons Tomato Paste
• 5 medium carrots (cut into chunks, about 1-inch)
• 1 lb. baby Yukon gold potatoes (halved or quartered)
• 2 bay leaves
• 1 sprig rosemary
• 1 cup frozen peas
• 1/4 cup Cold Water + 3 tablespoons Corn Starch (Optional)
• 2-3 drops Gravy Master ((Optional)- Adds an even richer darker color.)