Place cauliflower florets into a food processor or blender. Pulse for about 10-20 seconds until cauliflower resembles a rice texture. Do not over pulse, or it will become mushy. Set aside.
Heat a large skillet over medium heat. Add 1 tbsp oil, then saute garlic and onion for 3-4 minutes. If using raw chorizo, add it here and cook for 4-5 minutes. Now add bell pepper and cauliflower rice. Continue to saute for 5-6 minutes, consistently stirring.
Now add tomatoes, paprika, saffron, salt, and chorizo. If using precooked sausage, slice into bite size pieces and toss into the mixture. Now add the shrimp.
Place white wine, lemon juice, and tomato paste into the skillet. Increase heat to medium high and bring to a quick boil. Now reduce the heat to a simmer, and let the flavors meld while the shrimp cooks. Continue to stir and cook for another 8-10 minutes.
Add the last 2 tbsp lemon juice and parsley (if using) for garnish. Serve warm.