Slow Cooker Sirloin Beef Tips in Mushroom Gravy!

Name: Slow Cooker Sirloin Beef Tips in Mushroom Gravy!
Total time: 1 h 15 min
Yield: 4 servings
Ingredients: 3 pounds sirloin high quality, cubed 1-1 1/2 inch in size; 2 cubes salted butter; 4 tablespoons olive oil divided; 1/2 pound sliced mushrooms; 1 teaspoon seasoning salt divided; 1 teaspoon white pepper; 1 tablespoon black pepper; 2 cups beef broth; 2 teaspoons dark brown sugar; 2 tablespoons worcestershire sauce; 2 tablespoons ketchup; 1 teaspoon dried thyme; 1 cup diced onion; 3 tablespoons water; 1 teaspoon adobo red top; 2 cloves garlic minced; 1 teaspoon parsley; 2 teaspoons gravy master; 2 tablespoons cornstarch