Start by peeling the Yukon Gold potatoes and cutting them into 3/4 inch dice. Place the diced potatoes in a large pot and cover them with cold water. Add in the baking soda. Bring the water to a boil and cook the potatoes for about 10 minutes, or until just tender but not falling apart. Drain and let them cool slightly.
In a large frying pan or skillet, heat 1/4 cup of olive oil over medium-high heat until hot but not smoking.
Carefully add the drained potatoes to the pan in a single layer. Season with salt and pepper. Fry for about 10-15 minutes, turning occasionally until golden brown and crispy on all sides. Use a slotted spoon to transfer to a paper towel-lined plate to drain excess oil.
In a separate pan, heat 2 tablespoons of olive oil over medium heat. Add the diced onion and sauté for about 5 minutes until translucent. Add the minced garlic and cook for another minute until fragrant.
Stir in crushed tomatoes, Spanish smoked paprika, cayenne pepper, and hot sauce. Season with salt to taste. Let the sauce simmer for about 15-20 minutes to meld flavors.
In a mixing bowl, combine mayonnaise, grated garlic, and lemon juice. Mix until well combined to make the garlic aioli.
To serve, arrange crispy potatoes on a platter, drizzle with spicy tomato sauce, add a dollop of garlic aioli, and garnish with chopped parsley if desired.