A poached egg on baked yogurt is a high-protein breakfast. Note: The eggs in this recipe are not fully cooked. It should not be prepared for pregnant women, babies, young children, the elderly, or anyone whose health is compromised.
Preheat oven to 350 degrees. Stir together yogurt, 2 tablespoons scallions, the garlic, salt, and 1/8 teaspoon pepper in a bowl. Spoon 1/2 cup yogurt mixture into each of four 6-ounce ovenproof dishes. Place on a rimmed baking sheet. Bake until yogurt is just firm, 10 to 15 minutes.
Meanwhile, fill a large straight-sided skillet with 1 inch water. Bring to a simmer over medium-low heat. Working quickly, crack each egg into a small cup, and gently slide egg into water. Simmer until whites are opaque but yolks are still runny, 2 to 3 minutes. Using a slotted spoon, transfer eggs to a plate lined with paper towels, and let drain.
Place 1 egg on top of each baked yogurt. Top with watercress, tomatoes, and remaining tablespoon scallions. Sprinkle with 1/4 teaspoon pepper and the paprika. Serve immediately with toast.