In a casserole pan, melt the butter. Add the onion & season it with smoked paprika, salt & pepper. Cook it for 5 minutes over medium heat, stirring occasionally.
Add the bacon to the pan & cook for 4 minutes, stirring frequently.
Add the potatoes, peas, spinach, vegetable stock & parsley to the pan. Bring to boil & then let simmer for 30 minutes.
Add the besciamella to the pan. Stir for 2 minutes over low heat.
Blend the soup until it has a smooth, creamy texture.