For the pasta and sauce: Bring a large pot of salted water to a boil. Cook the pasta according to the package instructions.
Meanwhile, melt the butter in a large skillet over medium heat. Add the pancetta, thyme, garlic and onions and cook until the onions soften, 2 to 3 minutes. Stir in the the lemon zest and juice and bring to a simmer. Stir in the peas and cream, bring to a simmer and simmer until slightly thickened, about 2 minutes.
For the pangrattato (crispy crumbs): Meanwhile, add the olive oil to a saute pan over medium-low heat. Add the panko, tossing to coat in the oil, and then season with salt and pepper. Cook, tossing occasionally, until the panko is golden brown, 3 to 4 minutes. Remove from the heat, add the lemon zest and thyme and stir everything together.
Stir the Pecorino into the lemony sauce, then drain the pasta, add it to the skillet of sauce and toss together. Taste and adjust the seasoning as needed.
Sprinkle the pangrattato over the pasta and garnish with the lemon wedges. Serve straight from the skillet.