In a small skillet over medium-high heat, add almonds and toast until golden brown, 5—6 minutes. Set aside.
Set a large skillet over medium heat. Add olive oil; when it sizzles, add scallions. Cook until translucent, about 3 minutes. Add garlic and continue cooking 30 seconds or until fragrant. Add peas, salt, and pepper. Cook 3—5 minutes, shaking skillet occasionally until peas are tender and water has evaporated.
Remove from heat; add lemon juice, feta, and toasted almonds. Toss gently to combine, and serve warm.