Place pumpkin seeds in a blender and blend for 30 to 40 seconds or until mixture is a powdery paste. Set aside.
Wash beef and cut into bite-size cubes. Season with salt. In large pot, heat oil over medium-high heat for 4 to 5 minutes. Add beef and saute for 5 minutes or until meat is brown but not cooked through.
Place tomatoes, onions, and pepper in a blender and blend for about 30 seconds or until smooth. Add tomato mixture to meat, reduce reduce heat to medium-low, and cover. Cook 50 minutes or until meat is tender
Add tomato sauce, water, and shrimp and simmer for 10 minutes.
Add spinach and ground pumpkin seeds and continue to simmer 10 minutes more.