In a large, heavy skillet, heat 2 tsp. oil over medium-high heat. Add tomatoes and garlic; cook, shifting pan occasionally, until tomatoes are lightly browned and blistered on all sides, about 4 minutes. Transfer to a bowl.
Heat remaining 2 tsp. oil in skillet. Add spinach, scallions, thyme and red pepper flakes; sauté until spinach is tender, about 5 minutes. Spread spinach evenly over skillet. Scatter tomatoes over spinach and sprinkle with salt and pepper. Pour eggs into skillet and turn off heat.
Immediately stir egg mixture with a heatproof spatula until eggs are gently scrambled, about 1 minute. Sprinkle with nutritional yeast, if desired, and serve hot.