How to Make It
Spread ricotta on a baking sheet lined with paper towels. Top with another layer of paper towels and set aside to absorb excess moisture, 15 minutes. Generously dust a baking sheet with semolina flour (cover surface completely).
Stir together ricotta, egg, egg yolk, cheese, 1 teaspoon black pepper, and ½ teaspoon salt in a large bowl. Add all-purpose flour; stir just until incorporated. Drop 1½-inch balls of dough onto baking sheet and dust tops with more semolina flour. Freeze, uncovered, for 30 minutes.
Bring a large pot of salted water to a simmer. Add gnudi and cook, gently stirring once, until tender and fluffy, 6 to 8 minutes. Using a slotted spoon, divide gnudi among shallow serving bowls. Reserve ⅔ cup cooking water.
Heat a medium skillet over medium. Add butter, lemon juice, crushed red pepper, remaining ¼ teaspoon each salt and black pepper, and reserved cooking water. Cook, stirring constantly, until sauce thickens, about 2 minutes. Add peas and mint; toss to coat. Spoon sauce and peas over gnudi. Garnish with additional mint leaves.