Toss the beets in a little olive oil, season with salt and pepper and spread on to a very lightly oiled rimmed sheet pan. Roast for 15 minutes.
Toss the kale with 1 1/2 Tbsp of olive oil, season with salt and pepper and stir in with the beets.
Season the shrimp with tarragon, mustard powder and a little salt and pepper then scatter the shrimp over the top of the vegetables. Bake for a further 15 minutes or until the shrimp is fully cooked,
Serve in bowls and sprinkle with the toasted sunflower seed kernels.