• Cut a small corner from the chorizo packaging and drain off any excess liquid. Transfer to a plate; pat dry with a paper towel.

In a large frying pan over medium-high heat, warm 1 teaspoon oil until hot but not smoking. Add the chorizo and cook, stirring to break up the meat, until lightly browned but not yet cooked through, 3 to 4 minutes. Using a slotted spoon, transfer the chorizo to a paper-towel-lined plate to drain. Do not clean the pan.
While the chorizo cooks, start preparing the remaining ingredients.

• Remove the stem, ribs, and seeds from the bell pepper; cut the pepper into ¼-inch-wide strips. 
• Peel and finely chop enough onion to measure ½ cup [1 cup].
• Cut the cauliflower lengthwise into quarters, discarding any leaves or thick stalks. Using a food processor fitted with the grater attachment, or the coarse holes of a box grater, coarsely grate the cauliflower. Alternatively, using a knife, cut the florets and tender stems into ¼-inch pieces. 
• Strip the parsley leaves from the stems; coarsely chop the leaves for garnish. 

In the same pan used for the chorizo, add the bell pepper and onion and cook over medium-high heat, stirring occasionally, until starting to soften, 2 to 3 minutes. Add the cauliflower “rice,” chorizo, and paella sauce base, season with salt and pepper, and cook, stirring occasionally, until the cauliflower “rice” starts to soften and the chorizo is cooked through, 3 to 5 minutes.

Transfer the paella to individual bowls and garnish with the parsley. Dollop each bowl with 1 tablespoon lemon aioli and serve the rest on the side.