Heat a large pan with oil, cook the onions until soft. Add the chicken, cooking until almost cooked through.
Add in the crushed garlic, lasagne sauce and season to taste.
Reduce the heat and simmer for 20 minutes. Set aside.
In a bowl, combine sour cream and cream cheese until smooth.
In a large dish assemble the lasagne, add a fresh layer of pasta sheets, followed by the chicken mixture and a third of the sour cream cheese mix. Repeat the process once more until the dish is almost full. Spread the remaining sour cream cheese mixture on top.