Step 1

Warm a teaspoon or two of olive oil in a large pot (at least 5 quarts) over medium-high heat. Add the onion and cook until translucent and just starting to turn golden-brown, 5 to 8 minutes. Add the potatoes and 1/4 teaspoon salt, and cook until the edges of the potatoes are beginning to soften, another 5 minutes.

Step 2

Clear a space in the middle of the pan and add the garlic, oregano, and cayenne. Cook until the garlic is fragrant, about 30 seconds, then stir into the onions and potatoes. Add the stock to the pan and bring to a boil. Reduce heat to medium-low, and simmer the soup until the potatoes are tender, 10 to 15 minutes.

Step 3

Add the corn kernels, peas, queso fresco, and milk to the soup. Bring back to a simmer (do not boil) and cook until the corn and peas are tender, another 5 minutes. Taste and add salt and pepper as needed.

Step 4

This soup will keep refrigerated for a week. If freezing, remove the portion of soup to be frozen before adding the milk.