How to Make It
Combine milk, yogurt, and 2 teaspoons vinegar in a microwave-safe bowl, stirring with a whisk. Microwave at HIGH for 4 minutes. Gently stir to form small curds. Strain mixture through a sieve over a bowl; let stand 5 minutes. Reserve 2 tablespoons liquid. Discard remaining liquid. Combine reserved liquid, solids, and 1/8 teaspoon salt in a small bowl.
Combine remaining 4 teaspoons vinegar, remaining 1/4 teaspoon salt, peas, mint, 3 tablespoons oil, and 1/4 teaspoon pepper in the bowl of a food processor; pulse until spreadable but still slightly coarse.
Place about 1 tablespoon pea mixture on each toasted bread slice. Top each piece with about 1 teaspoon ricotta mixture. Sprinkle toasts evenly with remaining 1/4 teaspoon pepper, and drizzle with remaining 1 tablespoon oil.