Peel the onion and cut it into pieces.
Heat a knob of butter or a splash of olive oil in a large cooking pot and sauté the onion.
Add the garlic and the sprig of thyme and bay leaf.
Sauté the peas briefly as well.
Add the chicken broth and bring to a boil.
Let it simmer for about 15 minutes on low heat.
Meanwhile, prepare the garnish. Cut the avocado in half and remove the pit. Slice the flesh down to the skin. Now scoop the avocado slices out of the skin with a spoon. Cut the slices into cubes. Pluck the leaves from the parsley and chop them finely if desired.
Heat a generous splash of olive oil in the pan. Fry the slices of baguette on both sides until golden brown. Let them drain on a plate with paper towels.
Remove the sprig of thyme and the bay leaf from the soup.
Blend the soup and season with pepper and salt.
Divide the soup among the plates and finish with the slices of baguette, the sour cream, the avocado cubes, and the parsley.