10 fresh jalapeno peppers, halved lengthwise and seeded
1 (12 fluid ounce) bottle Mexican beer
1/2 cup water, or as needed
1 clove garlic
1 slice onion
salt to taste
Place the tomatoes and jalapenos into a saucepan, and pour the beer over them. Add enough water so that the tomatoes and jalapenos are covered. Simmer over medium heat until soft. Remove from heat, and let cool slightly.
Transfer the tomatoes and jalapenos to a blender, and add the garlic and onion. Pulse until well blended. Add some of the cooking liquid to help with blending if necessary. Taste, and season with salt.