Peel potatoes and cut into 1 1/2 inch pieces. Place them into a pot of cold water under medium high heat. Add salt and bay leaf. When potatoes are fork tender take them out and drain them. Let them steam dry for 10 minutes.
In a separate bowl, take the pot of hot water used for the potatoes and use it as a double boiler to melt your butter and sour cream. Use a potato ricer to press potatoes through and onto your melted butter and sour cream. Add salt and black pepper to taste. Gently mix everything together. If you prefer your mashed potatoes a little more slack, you can add a bit of milk or cream. Be sure to not over mix. Mashed potatoes tend to turn gummy in texture if you over mix them.
Pat your steaks dry with a paper towel and salt and pepper them liberally. Heat up your cast iron pan. When it is very hot, add olive oil and gently place your steaks on the pan and let them sear for 2 to 3 minutes on each side (for medium-rare). Be sure to also sear the sides as well.
When the steaks are halfway cooked, add butter, smashed garlic, rosemary and thyme. Tilt your pan and use a spoon to scoop up the melted butter to baste the steaks. Continue to baste the steaks as they finishing cooking. If you are not sure if the steaks are done to your liking, stick a thermometer in the center:
When they're done, pull the steaks out and allow them to rest on a wire rack for least 10 minutes. Cut the steaks into slices.
Melt butter in a pan under medium heat. Add spinach, salt and black pepper. When the spinach leaves are wilted down, it's done.
In a sauce pan, heat up beef stock to boil and reduce to simmer. Simmer until stock is reduced to about 1/4 cup. Add butter and salt & pepper to taste.
Use a ring mold to help plate the food "Napoleon" style (in layers). Place the ring mold in the center of the plate. Scoop some mashed potatoes into the ring mold to form your base, followed by a layer of spinach. Then place 5 steak slices on top. Gently remove the ring mold. Drizzle the sauce around the presentation. Dinner is served!