Preheat oven to 400 degrees. Spread almonds on a baking sheet; place in oven. Toast until almonds are golden and fragrant, 8 to 10 minutes. Remove from oven; let cool completely. Transfer half the almonds to a cutting board, and chop coarsely. Place remaining half in the bowl of a food processor fitted with the metal blade; process until almonds are finely chopped, 15 to 20 seconds. Add coarsely chopped almonds, and stir to combine.
Melt butter in a large skillet over medium heat. Add peas, lemon juice, salt, and pepper; stir until all ingredients are well combined and heated through, about 2 minutes. Sprinkle with almonds, and toss to coat. Transfer to a serving bowl, and serve.
I made 1 minor change. I used sliced almonds to skip a step. It was very nice and I used up the last harvest of peas of my plant.