In a large sauce pot, combine all ingredients, except cornstarch slurry. Blend ingredients together with an immersion blender. Heat over medium heat slowly, blending often, just until sauce reaches 180°F. With immersion blender working in sauce, pour cornstarch slurry slowly into sauce to equally distribute. Heat just until sauce begins to thicken. Do not boil. Allow to cool and transfer to a squeeze bottle.
Cut the green leaves off the cauliflower (or romanesco, if using) and trim core flush with the bottom.
Using a sharp knife, cut steaks approximately 1 1/2-inch-thick, keeping core intact. Arrange steaks in rows on a parchment lined sheet pan as you would any steaks or chops. Blend peanut and sesame oils, then brush both sides of steaks and season with salt and pepper. Steaks can be roasted in a hot oven on a stone, seared in a preheated cast iron skillet, or grilled on a charcoal grill. Allow steaks to take a heavy char, brushing with oil as needed. Roast or grill until steaks are tender when piercing with a sharp knife.
Peel ginger knobs and shave lengthwise using a mandolin into very thin slices. Julienne ginger slices and fry in hot oil until golden brown.
Note: The ginger will disperse quickly in the oil, so it’s best to contain it in a fry basket, pasta basket, or a Chinese/Japanese noodle basket/strainer.
Pour tomatoes into a large mixing bowl, drizzle with peanut-sesame oil and season with salt and pepper.
Toss to combine and transfer to a parchment-lined sheet pan.
Roast in a preheated 400°F oven for 5 to 10 minutes, or just until the skin is blistered and the tomatoes start to “melt”. Remove tomatoes from oven, drizzle with Kikkoman Soy Sauce and cool.
In a hot pan, sauté spinach in peanut-sesame oil blend until just wilted.
Arrange hot grilled steaks on a large plate or on a wooden board. Garnish with wilted spinach, roasted tomatoes and a plouf of frizzled ginger. Drizzle generously with steak sauce.