Put the oven rack in the upper middle position and heat the oven to 500 degrees. Toss the Brussels sprouts with oil, water, 3/4 t salt and 1/4 t pepper, until coated. Transfer the sprouts to a rimmed baking sheet, with cut sides down.
Cover the sheet with aluminum foil and roast for 10 minutes. Remove the foil and continue roasting until the sprouts are well browned and tender, 10 to 12 minutes more. Season with salt and pepper.
1. While sprouts are roasting, heat 3 T olive oil in a skillet over medium heat. When shimmering, add 2 minced garlic cloves and 1/2 t red pepper flakes, cooking until garlic is golden and fragrant, about 1 minute. Remove from heat. After sprouts are done, toss with the garlic and pepper flake oil and season with salt and pepper. Sprinkle with 1/4 c Parmesan cheese before serving.
2. While sprouts are roasting, cook 4 slices of bacon until crisp. Transfer bacon to paper towel lined plate and reserve 1 T of bacon fat. Finely chop bacon. When sprouts are done, toss with 2 T olive oil, reserved bacon fat, chopped bacon and 1/2 cup finely chopped toasted pecans. Season with salt and pepper.
3. Toss roasted sprouts with 3 T melted unsalted butter, 1 T lemon juice and 1/3 cup finely chopped toasted walnuts. Season with salt and pepper.
Combine lemon juice, mustard, shallot, garlic, salt and a pinch of pepper in a small bowl. Stir to blend, then set aside to let flavors blend. Mix sliced kale and sprouts in a large bowl. From the 1/2 c of olive oil, take 1 T and heat in a small skillet over medium high heat. Add almonds and stir frequently until golden brown in spots, about 2 minutes. Drain on a paper towel lined plate. Sprinkle almonds with salt. Whisk remaining olive oil with lemon/mustard mixture. Season with salt and pepper as needed. Add to kale and sprouts, with cheese, tossing to coat. Garnish with almonds.