Begin by preparing the beef seasoning mixture and assembling all required ingredients for the gravy. Ensure that each component is measured accurately for optimal results.
Proceed to trim the sirloin tips, cutting them into uniformly sized 1-inch cubes and removing any excess fat.
In a mixing vessel, combine the previously mentioned beef seasoning and thoroughly coat the meat cubes. Subsequently, sprinkle flour over the seasoned meat, ensuring an even distribution.
Place a large skillet over a medium-high heat source and introduce the olive oil. When the oil is sufficiently heated, brown the meat in batches, taking care not to overcrowd the skillet. Each side should be seared for approximately 30-45 seconds. It may be necessary to add additional oil between batches. Once browned, transfer the meat to a separate dish and set aside.
Utilize the red wine to deglaze the pan, carefully scraping any browned bits—known as "fond"—from the bottom of the skillet. This is essential for imparting depth of flavor to the gravy.
Once the wine has reduced by half, lower the heat to a medium level and incorporate the butter and diced onions, cooking until the onions are soft.
Introduce the minced garlic to the skillet, cooking for a brief duration of one minute, ensuring it does not burn.
Add the remaining ingredients for the gravy, with the exception of the cornstarch mixture, and bring the concoction to a boil.
Gradually whisk the cornstarch mixture into the gravy, stirring constantly to achieve a smooth consistency. Adjust the quantity to obtain the desired thickness.
Finally, lower the heat to a medium-low setting and reintroduce the beef along with any accumulated juices to the skillet. Cover the skillet partially and allow the mixture to simmer for 10-15 minutes until the beef is thoroughly cooked.
If desired, enhance the sauce by incorporating a tablespoon of cold butter, stirring until it is fully integrated and the sauce achieves a smooth and velvety finish.
Serve the beef tips and gravy over a bed of mashed potatoes, egg noodles, or rice, as preferred.