Preheat oven to 400°F. In a baking dish, place tomatoes cut sides up. Mist with cooking spray and season with salt and pepper. Roast until tender and slightly shriveled, about 30 minutes.
Meanwhile, place a heat-proof bowl over a pot of simmering water; in bowl, whisk together egg yolks, yogurt and lemon juice. Cook, whisking often, for 5 to 8 minutes or until thick. (NOTE: mixture will appear thick at first, then will thin out and thicken again.) Remove bowl from heat and whisk in 4 tsp butter and mustard until smooth. Season with additional salt. Cover and set aside.
In a large skillet on medium high, heat remaining 1 tsp butter. Add mushrooms and cook, stirring, until softened, 3 to 4 minutes. Add spinach and cook, stirring, until spinach is wilted, 1 to 2 minutes. Remove from heat, cover and set aside.
Poach eggs: Fill a large, shallow saucepan with 3 inches water; bring to a boil. Add vinegar and reduce heat to medium-low to maintain a gentle simmer. In a small dish, break 1 egg and gently slip into simmering water. Repeat with remaining eggs and cook for 3 to 4 minutes, or until desired doneness. (NOTE: It may be easiest to do this in 2 batches of 4 eggs each.)
Divide spinach-mushroom mixture among plates and nestle 2 baked tomato halves on top. Top each tomato with a poached egg, then spoon sauce over top and sprinkle with chives.
Serving Size: 2 eggs and 1/4 of spinach mixture, tomatoes, and sauce
Eggs and arrowroot starch help hold these California-fresh patties together, while quinoa, scallions, lemon zest and dill give them flavor and a nutrition boost. If desired, set aside a few tablespoons of the homemade dressing to use as a dipping sauce or drizzle over the patties.
We add depth to the Tetra Pak tomatoes by simmering them with onions, tomato paste, garlic and red pepper flakes. This process also thickens the sauce so it lightly coats the penne instead of drowning it.