Heat the avocado oil in a large stockpot over medium high heat. Once the oil is hot, add the stevia seasoning, the Italian herbs and bay leaves. Stir for a few second to mix and heat.
Add the tomato paste. Stir to mix.
Add the carrot and celery and garlic if using. Cook, stirring for 1-2 minutes until vegetables are slightly cooked.
Add the chopped seasonal vegetables and stir to combine. Cook, stirring, for a minute.
Pour in the canned diced tomatoes. Stir well to mix.
Raise heat to high and add the 6 cups of stock. Cover and bring the mixture to a boil. Once boiling, reduce heat to a simmer. Let simmer for 30 minutes, stirring often.
Add the pasta and beans. Stir to combine. Cook for 10-12 minutes or until pasta is el dente. Add the greens and just cook until they are wilted, about 1 minutes.
Remove the pot from the heat and remove the bay leaves. Stir in the lemon juice. Taste and season with more seasonings and freshly ground black pepper as desired.
Spoon into serving bowls, garnish with chopped parley or basil and serve immediately.