In a medium bowl, mix garlic, anchovy, mustard, yeast, and parmesan; combine until it forms a smooth paste. Using a whisk, slowly drizzle in the olive oil, whisking vigorously. Whisk in lemon juice, until well combined. Add sour cream and whisk until well combined. Set aside.

In a large bowl, combine grapes, kale, fennel, and dressing. Toss gently to ensure the dressing coats all fruits and veggies in the bowl. Plate salad evenly across 4 plates. Top salad with grated pecorino cheese and serve immediately with a piece of crusty toasted grilled baguette.