Pre-heat oven to 350f degrees.
Peel potatoes and slice thinly, preferably using a mandolin or slicer to a medium thickness. Make them all the same size to cook evenly.
Line a baking sheet with parchment paper and drizzle a little olive oil on top (approx. 1 Tbsp). Add potatoes in as close to a single layer as you can get it and toss in the olive oil. Sprinkle with sea salt and bake in the oven on a middle rack, for 15-20 minutes until cooked (but not crispy).
In the meantime, slice shallots and peppers into small rings of even sizing. Remove seeds and stem from peppers and discard.
Prep a non-stick, oven-safe pan (approx. 12 inches in size) with the rest of your olive oil over medium heat.
Add sliced shallots and peppers, season with salt and pepper to taste and stir frequently with a wooden spoon to get the veggies nice and tender (avoid getting them brown, you can lower the heat if needed).
Once potatoes are done, add to the pan and pat all veggies down in an even layer, reduce heat to medium-low for a couple of minutes.
Whisk 6 eggs in a mixing bowl until well combined. Season with salt and pepper to taste.
Reduce heat to low and pour eggs over veggies, with a spatula, slide the veggies a bit to ensure the egg mixture is getting into the corners and crevesis.
Place your skillet in the oven at the same temperature on a top rack and allow to cook for approx. 8 minutes.
Check your tortilla at the 8-minute mark, the top should be set but not too brown. Remove from the oven and carefully slide your spatula along the perimeter of the skillet, getting under the tortilla. Slowly inch your way totally underneath and ensure it’s not sticking.
Grab a large plate to cover the top of your skillet, and carefully with oven mitts, flip the pan over onto the plate to reveal your tortilla!
Garnish as you wish with more seasonings and herbs, serve or store in your fridge.