When preparing the Vegan Egg Yolk you can add 1 - 2 teaspoons more cornstarch if you want the yolk to be thicker.
Turn the block of tofu on its side and cut into 4 - 6 thin slices. Use the tip of your knife to cut off the corners of the tofu making it a rough circle. You could alternatively use a round cookie cutter, or just leave it as a rectangle.
Melt the vegan butter in a frying pan over medium heat. Add in the tofu slices in a single layer (you may have to work in batches). Fry the tofu a couple of minutes per side until lightly browned around the edges, flip and repeat on the other side.
Once the tofu slices are cooked, remove from pan and place directly onto plates or serving dishes. Use a small round cookie cutter, a shot glass, or the tip of your knife to cut a small circle in the middle of the fried tofu slices. Serve the slices on a plate and fill the holes with the Vegan Egg Yolk. Garnish with salt and pepper as desired. You can serve any leftover dipping sauce in a small dish on the side.