Meanwhile, in a large, deep saute pan, sizzle the garlic in the olive oil over medium-low heat and cook until the garlic starts sizzling with little bubbles around it, 1 to 2 minutes. Add the marinara sauce, a heavy pinch of salt, and a scrunch of pepper. Increase the heat to medium-high, add the oregano, and simmer for a minute or two before adding the beef. Submerge the meat in the simmering sauce and cook until soft and tender, about 10 minutes.