Preheat the oven to 400 degrees. Coat a cast iron skillet with olive oil cooking spray.
Season the baby potatoes, onion, and garlic slivers with olive oil and crushed red pepper flakes, sea salt, and freshly cracked pepper, to taste; toss to coat evenly.
Pour into the prepared cast iron skillet.
Place into the oven and roast for 10 minutes.
Flip potatoes with a spatula then continue to roast for another 10-15 minutes.
Add the asparagus and tomatoes and continue to roast, making sure to flip with a spatula every 5 minutes, until golden brown and fork tender, about 10 minutes.
Remove from the oven and add the spinach to the skillet, stirring gently for a minute or two, until wilted.
While the veggies are roasting, heat 1 ½ inches of water and 1 teaspoon of white vinegar in a wide medium sized saucepan and bring to a simmer.
When you remove the veggies from the oven, break 1 egg into a small ramekin.
Once the water is at a simmer, stir the water with the bottom of your slotted spoon clockwise to make a swirling motion in the water.
Quickly and carefully slide egg into the water.
Cover and turn stove off.
Poach until whites are firm and yolks are still runny, 3 minutes and 45 seconds to 4 minutes. Remove the egg using a slotted spoon and drain a bit over the pan.
Serve the roasted veggie and baby potato hash in a bowl topped with the poached egg. Season the egg with sea salt and freshly cracked pepper, to taste.
Serve immediately. Enjoy!!!
Side Note: To cut down on the roasting time for the potatoes, par cook them in boiling water for 7 minutes before roasting.