Heat olive oil in a large pan over a medium heat. Add pastrami chunks and sauté until browned. Add Brussels sprouts and cook, stirring frequently for about 10 minutes, until they become browned in some parts. Stir in lentils and remove from heat. Season with sea salt.
Whisk together ingredients for dressing in a small bowl or jar.
Place Brussels sprouts with lentils in a large bowl. Add dressing and chopped parsley and mint, mix well to combine. Serve warm.