Preheat oven to 350. Slice ¼” off the top of the garlic head. Place in a foil square (or a small, lidded ovensafe dish) with a splash of olive oil and water. Roast until cloves are soft and sticky, about 1 hour. Let cool completely in the foil
Pop the roasted and raw garlic cloves, mustard, vinegar, egg yolks, and anchovies in a blender jar. Blend until smooth, then with the motor running on low, slowly drizzle in olive oil. Adjust seasonings, if needed, with salt, pepper, and vinegar.
Combine kale with the dressing (you may not need all of it). Massage dressing into the greens until wilted, about a minute. Toss the sauerkraut and apple through.