1. TOASTING AND ROASTING THE KEY INGREDIENTS:
Set a heavy ungreased skillet or griddle over medium heat. If using dried chiles, break off their stems. Toast the chiles a few at a time: Lay on the hot surface, press flay for a few seconds with a metal spatula (they'll crackle faintly and release their smoky aroma), then flip and press down to toast the other side. Transfer the toasted chiles to a bowl, cover with hot water and let rehydrate for 30 minutes, stirring regularly to ensure even soaking. Pour off all the water and discard.
If using canned chiles, simply remove them from the adobo they are packed in.
On a heavy, ungreased skillet or griddle over medium heat (same one as above), roast the unpeeled garlic, turning occasionally, until blackened in spots and soft, about 15 minutes. Cool, slip off the papery skins and roughly chop.
Lay the tomatoes on a aking sheet and place about 4 inches below a very hot broiler. When they blister, blacken and soften on one side, about 6 minutes, turn them over and roast on the other side. Cool then peel, collecting all the jjuices with the tomatoes.

2. THE SAUCE:
Scrape the tomatoes and their juices into a food processor or blenderand add the rehydrated or canned chiles and garlic. Pulse the machine until the mixture is nearly a puree- it should have a little more texture than canned tomato sauce.
Heat the lard or oil in a heavy, medium -size (2 to 3 quart) saucepan over medium-high heat. When hot enough to make a drop of the puree sizzle sharply, add it all at once and stir for about 5 minutes as it sears and concentrates to an earthy red thickish sauce -about the consistancy of a medium-thick spaghetti sauce. Taste and season with salt.

NOTE: You can replace the chipotles with dried cascabel, arbol or dried serrano chiles.

From: Rick Bayless's Mexican Kitchen
Posted By:
Post Date:6/23/99