Make the sauce. In a small bowl, stir together Greek yogurt, ketchup, mustard, chopped pickles, pickle juice, paprika, salt, and pepper. Taste and adjust.
Chill while you cook.
Prep your bowl base. Chop lettuce, slice tomatoes, pickles, and red onion. If using rice or cauliflower rice, warm it and set aside.
Sauté aromatics. Heat oil in a large skillet over medium. Add diced onion with a pinch of salt.
Cook 3–4 minutes until softened, then add garlic and cook 30 seconds until fragrant.
Brown the chicken. Add ground chicken, breaking it up with a spoon. Season with salt, pepper, paprika, onion powder, and garlic powder. Cook 6–8 minutes until no longer pink and slightly browned.
Add burger flavor. Stir in tomato paste, mustard, and Worcestershire.
Cook 1–2 minutes to caramelize the paste. If the mixture looks dry, add a tablespoon of water to loosen.
Melt the cheese. Reduce heat to low, sprinkle cheese over the chicken, and cover for 1–2 minutes until melted and gooey. Remove from heat.
Assemble bowls. Add lettuce (and rice or cauli rice if using) to each bowl.
Top with a generous scoop of the cheesy chicken, then add tomatoes, pickles, red onion, and avocado.
Finish with sauce. Drizzle the special sauce over the top. Add extra mustard or hot sauce if you like heat. Serve immediately while the chicken is warm.