This is from the first paragraph of the novel, so we can expect it to establish background, raise questions, and intrigue the reader.
It is written in the first person, so we are getting the thoughts of the narrator, and the mode is stream of consciousness: that is, an attempt to depict the unfiltered flow of thought, of images, ideas and feelings quickly passing through the narrator’s mind. Let’s look in detail at the text.
Yes, he was dark.
We assume that he is a man known to the narrator. Dark could mean dark-featured, dark-skinned, dark-haired, dark-tempered, or some or all of them. Who is he? Someone important in the novel, we expect.
He still is except that it is not easy to think of him as still existing, and everywhere my gaze turns he isn’t there.
He has gone away. Or died? (Though “he still is” makes this seem less likely.) It seems that the narrator was close to him, and is continually reminded of his absence. He may be the father or son or lover of the narrator; based on the title of the novel we suspect the last.
What’s the expression? Water, water everywhere…
The narrator tries to remember a quotation from The Rime of the Ancient Mariner (1798) by Samuel Taylor Coleridge:
Water, water, every where,
And all the boards did shrink;
Water, water, every where,
Nor any drop to drink.
Why did this quotation occur to the narrator? In Coleridge’s poem, the sailors have been drifting in the ocean, until “every tongue, through utter drought, / Was withered at the root”. They are surrounded by water and yearning desperately for it, but it is salt and they cannot drink it. So in Peel My Love Like an Onion the narrator is likely also yearning for something that can’t be had, and we can guess that this is the dark man.
I was full—
Full of what? In the context of the allusion to The Rime of the Ancient Mariner, full of love for the dark man.
Now the idea of fullness suggests to the narrator other things that can be full, in a process of free association.
a huge pre-Columbian pot,
‘Pre-Columbian’ refers to the cultures of the Americas before they had significant contact with Europe. So what suggested ‘pre-Columbian’ to the narrator? Maybe the narrator is native American? Or the dark man is? Or the narrator lived somewhere where pre-Columbian earthenware could be seen or found.
a copal-burning brassier,
Copal is an aromatic resin that is burned in central American religious ceremonies, and brassier must be a variant spelling of brazier. Again, this suggests that narrator is native American or has spent time with native Americans.
a funeral urn,
By association of incense-burning with funerals, the narrator recalls that someone died; perhaps the dark man.
a well, Jill’s bucket up and down,
The narrator remembers the nursery rhyme:
Jack and Jill
Went up the hill
To fetch a pail of water
Jack fell down
And broke his crown,
And Jill came tumbling after
“Broke his crown” is again suggestive of death. “Jack” could represent the dark man and “Jill” the narrator.
a bruja’s kettle simmering over the fire.
Bruja is Spanish for witch. Conventionally witches brew potions in kettles or cauldrons. The image is sinister, perhaps suggested by the images of death. The use of the Spanish language suggests that the narrator is from a Hispanic background.
That’s a lot of material for such a short paragraph! Of course we can’t be sure that we’ve correctly understood everything in this dense sequence of allusions and associations. Not everything that passes through someone’s mind is significant. But we have a rough feeling for the character and background of the narrator, and some hypotheses and forebodings about what is to come.