Scoop out the flesh of the two avocados in to the bowl in which you will serve the pasta. Mash the avocado flesh well. Add the lemon juice and mash again. Add the crushed garlic and stir. Add the seasoning to taste, followed by the olive oil, and mash thoroughly to make a creamy sauce.
Cook the pasta to al dente consistency in plenty of boiling water. Drain well and add to sauce. Toss thoroughly and serve.
Note: you can use more or less lemon jice, garlic or olive oil according to your family's taste.