Place the cauliflower florets in a food processor and pulse until they reach a rice-like texture; transfer to a bowl.
Heat the olive oil in a large skillet over medium-high heat.
Add the riced cauliflower to the skillet and cook, stirring occasionally, until it begins to brown, about 5–6 minutes.
Sprinkle in the fajita seasoning and salt, stir, and cook for 1 minute to toast the spices.
Pour in the salsa and continue cooking, stirring, until the mixture reduces slightly and is no longer very wet, about 3–4 minutes.
Remove from heat, stir in the chopped cilantro, squeeze fresh lime juice over top to taste, and serve.