bunches inexperienced onions, root ends trimmed, darkish inexperienced tops minimize off and discarded
pound or three 6-ounce packages child portobello mushrooms
tablespoons olive oil
Whisk wine, soy sauce, garlic, and 1 teaspoon dry mustard in giant glass baking dish. Add tri-tip and switch to coat with marinade. Let stand at room temperature half-hour, turning meat often.
In the meantime, whisk honey, 2 tablespoons water, 1/4 teaspoon salt, and remaining 2 tablespoons dry mustard in small bowl to mix; set sauce apart.
Preheat oven to 450°F. Take away tri-tip from marinade; pat dry with paper towels. Place tri-tip on giant rimmed baking sheet; sprinkle with salt and pepper. Organize inexperienced onions and mushrooms round meat; drizzle onions and mushrooms with olive oil. Roast 12 minutes. Flip meat, onions, and mushrooms over; roast till greens are tender and instant-read thermometer inserted into heart of meat registers 125°F for medium-rare, about 12 minutes longer.
Place mushrooms and inexperienced onions on platter. Minimize meat into 1/4-inch-thick slices; organize atop inexperienced onions and mushrooms. Pour any pan juices over. Drizzle calmly with mustard sauce. Serve, passing remaining mustard sauce alongside.