Preheat oven to 450F.
Heat a large cast-iron or oven-safe skillet over medium to medium-high heat. Add 1 tablespoon EVOO, one turn of the pan, and add sausage. Brown the links a few minutes on each side to crisp casings then remove to a plate.
Add another tablespoon EVOO, a turn of the pan, along with the onions and garlic, and season with oregano, salt and pepper. Cook onions to soften, 6-7 minutes, then add tomatoes and beans, and stir to combine.
Nestle the reserved sausages back in the pan and transfer to oven for 10 minutes to finish cooking sausages through. Wrap pita or flat breads in foil and place in the oven for 2-3 minutes before removing sausages.
Meanwhile, combine spinach with feta and olives, and dress with lemon juice and remaining 2 tablespoons EVOO and black pepper.
Garnish the sausage and beans with the parsley and serve with spinach salad and warm bread alongside.