Cook macaroni according to package directions; drain.
Heat large skillet over medium-high heat. Add olive oil, chicken and onion. Cook 6-8 minutes, or until chicken is no longer pink.
Reduce heat to medium. Stir in semisoft cheese. Gradually add milk and flour. Continue stirring and cooking until mixture is thickened and bubbly.
Reduce heat to low. Add hot sauce, cheddar cheese and cooked macaroni. Cook and stir 1-2 minutes until cheese is melted. Stir in spinach.
Top with cherry tomatoes and serve.