Heat olive oil in a skillet over medium-high heat. Saute garlic in hot oil until fragrant and slightly softened, about 2 minutes. Add diced tomatoes, vegetarian ground beef crumbles, and taco seasoning; cook and stir until tomatoes are soft, about 10 minutes.
Divide lettuce between two bowls and top each with half the tomato mixture. Surround tomato mixture with cottage cheese and sprinkle Cheddar cheese over the top; season with taco sauce.