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 3 to 5 minutes or until 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 heat to medium-low, and cover. Cook for 40 to 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.