Place a large pot over medium heat and add the olive oil.

Once the oil shimmers, add the diced onions and sauté until translucent, about five minutes.

Add the minced garlic and cook for another sixty seconds.

Pour in the vegetable broth and bring to a gentle boil.

Add the broccoli florets and chopped stems, reduce heat, and simmer for about ten to twelve minutes until tender.

Remove from heat and let cool slightly.

Blend the mixture until smooth, then stir in the Greek yogurt and fresh mint leaves.

Add lemon juice, salt, and pepper, and blend again to incorporate.

Pour into a large glass bowl, cover tightly, and refrigerate for at least three to four hours before serving.