If the frozen riced cauliflower is a solid block, let it sit a few minutes to soften and break it up; press in a clean towel or paper towel to remove obvious excess moisture if needed.

Place the 1 pound ground chicken in a large mixing bowl and break it up slightly with a spoon or your hands. Sprinkle with 1 teaspoon kosher salt and 1/2 teaspoon smoked paprika.

Add 1/2 cup frozen riced cauliflower, 1/4 cup chopped onion, 1/4 cup packed chopped parsley, 3 minced garlic cloves, and 1 large egg to the bowl. Mix just until the ingredients are combined; avoid over-mixing.

Divide the mixture into 16 equal portions (about 1 1/4 ounces each) and gently roll each portion into a ball. Handle gently so the meatballs hold together without becoming compacted.

Heat a heavy-duty, large nonstick skillet with tall sides over medium-high heat until hot.

Spray the skillet with olive-oil cooking spray. Place the meatballs in a single layer without crowding the pan (work in batches if necessary). Cook, turning occasionally, until browned on all sides, about 6 minutes total.

Pour in both jars (2 × 10 oz = 20 oz) prepared mild harissa sauce. Increase heat just until the sauce comes to a simmer, then reduce heat to medium-low.

Simmer the meatballs in the harissa sauce, uncovered or partially covered, for 20 to 25 minutes, until the meatballs are cooked through and the sauce has reduced slightly. Check that the internal temperature of the meatballs reaches 165°F (74°C).

Remove from heat and serve.