Mix flour, salt, yeast and sugar in a large bowl. Add yogurt, 4 tablespoons melted butter and water and mix to form a soft dough.
Knead 10 minutes until the dough is smooth and elastic.
Set it in an oiled bowl, cover it with a tea towel and let it rise for about an hour and a half.
Preheat oven to 475 F (give it 45 minutes to really reach that temperature).
Punch down the dough and roll it into 8 equally sized balls. Let these rest for 10 minutes.
Roast 4 whole garlic cloves, skin and all, in a shallow pan, until garlic is soft, about 5 minutes.
While garlic is cooling, roll out the first few balls of dough into flat ovals on a pizza stone or parchment paper. Then remove garlic skin and mince the roasted garlic. Mix garlic into 4 tablespoons melted butter, along with a few pinches of cardamom, to taste.
Brush dough lightly with melted butter, being careful not to drip any onto the parchment paper (otherwise the oven and kitchen will get very smoky!)
Bake for about 7 minutes, until naan is golden with puffy bubbles.