Preheat oven to 375ᵒ F.
Toss cauliflower with 2 teaspoons olive oil. Place on lined cookie sheet or in a large flat casserole dish. Roast for 15 minutes.
Place quinoa and 1/3 cup water in a medium saucepan. Bring to a boil and reduce heat to low. Simmer until liquid is absorbed, about 15 minutes. Set aside.
While cauliflower and quinoa are cooking, sauté onions in 1 teaspoon olive oil in a small skillet over medium-high heat.
Drain and rinse chickpeas. Place in a food processor with tahini, lemon juice, and water. Pulse until consistency is that of hummus. Start with 1/3 cup water, adding more if necessary.
Transfer the mixture to a large mixing bowl. Add quinoa, oregano, and sautéed onions.
When cauliflower is finished roasting, place in food processor and pulse until mealy. Add to chickpea mixture and mix thoroughly. Place hash in a large casserole dish and put it back in a 250-degree oven to keep warm while you make the gravy and the broccoli.
Sear mushrooms in vegetable broth until fork tender.
Steam broccoli in large saucepan.
While broccoli and mushrooms are cooking, make the gravy.
Put all ingredients in a blender. Blend on high speed for one minute.
Place in a large skillet over medium heat.
Whisk continually until gravy thickens. Adjust salt and pepper to taste.
If the color is not brown enough to your liking, add more Kitchen Bouquet.
Note: Kitchen Bouquet is a commercial flavoring and coloring product found in grocery stores.
Place two tablespoons gravy on a plate.
Put a portobello mushroom, upright like a bowl, in the middle of the gravy.
Place 3/4 cup hash on the portobello mushroom.
Drizzle it with brown gravy.