Position a rack in the upper third of the oven and preheat to 400 °F (200°C). Prick the potatoes with a fork and place them directly on the oven rack.  Bake until tender when pierced with a small knife, about 1 hour. Remove from the oven and let cook for 5 minutes. Reduce the oven temperature to 350 °F (180°C)

➤  4 large russet potatoes about 2 1/2 lb (1.25 kg) total weight, scrubbed and patted dry;

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➤ 6 Tbsp (3 oz/90g) unsalted butter;
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➤ 2 large cloves garlic, minced;
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➤ 1 large shallot, minced;

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➤ 2 bunches fresh spinach leaves, tough stems removed and leaves rinsed well;

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 ➤ 2 Tbsp sour cream;
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➤  salt and freshly ground pepper;

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➤ 1 cup (4 oz/125 g) firmly packed shredded extra sharp cheddar cheese;

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