Cut the tomatoes in half and put them in a small roasting tray. Add the garlic (whole and unpeeled) and tuck in the chilli.
Season with salt and pepper, drizzle with a little olive oil, then bake in a medium hot oven for about 25 minutes, until the tomatoes & garlic cloves are soft and the skin of the chilli has browned.
Remove the tray and let the vegetables cool. ( These three steps can be done hours/day ahead, but do keep the vegetables chilled).
Put the tomatoes into a small food processor, push the garlic flesh out of the skin and add to the tomatoes. Cut the chilli in half, discard the pip if you don’t want your dip to be too spice. Scoop out the flesh and add to the tomatoes.
Cut the avocado and lime in half. Remove the avocado stone, then scoop out the flesh and add it to the blender. Squeeze in the lime juice. Blend for a few seconds.
Add the cooking juice of the roasted tomatoes and the coriander leaves. Season with salt and pepper, then add the spices (paprika and/or cumin), if you like. Blitz again until you get the desired texture - the dip can be smooth or rough.
Taste, and adjust the seasoning, heat and lime juice ( you can add a drop of Tabasco, if it’s not spicy enough to your liking).
Chill until you’re ready to serve.