Heat the oven to 375°F/190°C. Heat the oil in a sauté pan and fry the shallots until soft and translucent. Add the garlic one minute. Remove to a plate. In the same pan, fry the bacon, and remove with the shallots. Divide the chard leaves from the ribs: chop the ribs quite small and shred the leaves. First, fry the ribs in the bacon fat until tender. (You may want to cover the pan for a few minutes to speed up the process.) Add the chard leaves to the pan, cover, and wilt, about 3 minutes.
Beat the eggs together with the crème fraîche. Season with salt and pepper. In a large bowl, toss the shallots, bacon, chard stems and leaves, cheese, raisins and pine nuts, to combine evenly. Taste, and season. Fill the tart shell with the vegetable mixture, and pour over the cream mixture. Bake until the tart has set, about 30 minutes. Remove from the oven and cool. Serve at room temperature.