This barbecue sauce has layered tastes. If prepared properly the initial taste will be of sweet and cinnamon. Once that passes one will experience the Guinness flavor which passes away in an intense wave of heat. Once the heat subsides one is left with the aftertaste that Guinness leaves in the mouth. It also happens to be vegetarian. Depending on your feelings on yeast, and a substitution of molasses for honey it can be vegan.
The quantity of items are not given. This should be about what tastes good to you. Besides cooking should be experienced, not followed out of a book. Life is no fun that way.
Preferably over a grill, if not then a saute pan will suffice, roast the jalapenos and onions. Ideally one would cook the jalapenos till they begin blistering on the outside, the onions till they are fairly well caramelized. Once they're finished cooking give the jalapenos and onions a quick dice
First run the tomatoes through a food processor till you have nothing but liquid. In a decent sized pot add the sherry vinegar approximately in a 1/5 ration of vinegar to tomatoe. Add enough honey to take the edge off of the vinegar. Put in the chopped jalapenos,garlic, and onions. Season with the cayenne, salt, and pepper. Simmer this until you have cooked out all of the water.
While the veggies/vinegar are cooking down, put on the Guinness. Pour the Guinness into a sauce pot and heat to a decent simmer. This is to reduce the Guinness and cook out the alcohol. Wait until you have the Guinness reduced to approximately half it's initial volume.
When the water is cooked out of the veggie mix and the Guinness is reduced to about half it's initial volume it's time to mix them. Ideally the final mixture should be approximately 1/4 reduced Guinness 3/4 veggie mixture. Once combined add the molasses(being generous), brown sugar, cinnamon, and cumin. Being somewhat liberal with the cinnamon and a touch more conservative with the cumin, a little goes a long way with cumin so take it easy.
Cook this just below simmer tasting occasionally and adding spices as necessary. Make sure to remember that salt can often bring out flavors that would become overpowering if more of the ingredient were added.
When the ideal taste has been reached slather it on the meat/veggie of your choice, cook and enjoy.
Having receieved multiple responses asking the amounts, I submit the following. But I do so with this caveat: I made this on the spur of the moment, as such all measurements will be guessed, and the amounts will be suitable to feed approx. 10 people with extra sauce to spare.
THESE ARE NOT EXACT!
tomatoes: 8 whole
chopped garlic: 2 cups
cumin: 2 tsp.
cayenne: 6 tbsp.
Guinness: 2 quarts
molasses: 1-1/2 cups
brown sugar: 1 cup+
salt: 5-6 tbsp.
sherry vinegar: 3/4 cup
honey: 1/2 cup
cinnamon: 3-4 tbsp.
onion: 2 onions