4 small onions
1 head garlic
2 cans stewed tomatoes with garlic
1/2 cup apple cider vinegar
Slice jalapenos into ~1cm pieces, roughly dice onions, peel and halve garlic cloves. (If you’re averse to spice, de-seed the peppers entirely or in part.) Place in skillet or pan, drizzle with olive oil, and roast on the middle rack on 400 degrees, stirring occasionally, until done.
Decant into large pot, add tomatoes, use vinegar to deglaze skillet, adding liquid to salsa. Salt liberally and simmer for ~20 minutes, until things have thickened a bit and the vinegar has mellowed into the veggies.
Pour into tupperware and store in the fridge for 24 hours before eating.
As I make it this is a spicy salsa, but not overly so. I like spice, but also like to eat salsa by the cup as a legit vegetable side with roasted meat, scrambled eggs, potatoes, and so forth; and this can be eaten copiously without inducing tears.