Coat a saute pan, over medium heat, with olive oil. Add the onion, season with salt, to taste, and toss in the crushed red pepper. Saute the onions until they are soft and very aromatic, about 4 to 5 minutes. Add the garlic and saute for 2 to 3 more minutes. Stir in the chorizo and cook for 2 to 3 minutes. Turn off the heat and stir in the bread crumbs. Let the mixture cool. When cool, add the Manchego and parsley. Taste and adjust the seasoning, if needed.
Preheat the oven to 350 degrees F.
Stuff the peppers with the filling and arrange them on a sheet pan. If there is extra stuffing, press a little on top of each of the peppers. Put the peppers in the oven to warm through, about 8 minutes.
While the peppers are in the oven, combine the arugula, almonds and scallions in a large bowl. Dress the salad with sherry vinegar, big fat finishing oil and salt, to taste. Check for seasoning and divide the salad between 4 serving plates.
Remove the peppers from the oven and arrange 2 peppers on each salad. Serve while the peppers are warm.