This is the Alton Brown guac recipe, and yes, it controversially uses tomatoes. I like extra veggies.
3 Haas Avocados (I had a bunch of small avocados from Trader Joe’s – I just used the 4 or 5 I had since they were on the teeny side)
1 lime, juiced
0.5t kosher salt
0.5t cayenne (yes, you can lower this amount if you find it too spicy)
0.5 onion, diced
0.5 jalapeño, diced (I remove the seeds – the cayenne gives it enough kick)
1 roma tomato (the recipe calls for 2, but that always seems like overkill to me)
1T chopped cilantro
1 clove garlic, minced
Scoop out the avocado pulp and put it in a large bowl with the lime juice, toss to coat. Add the spices, then use a fork (or your potato masher if you have one) to mash everything together. Fold in all the other ingredients. Let it sit for an hour, then serve.