This is about the cheese, melted into a tender eggs-and-butter base with caramelized onion underneath. One pan, twenty minutes, and that wedge transforms into dinner for two.

Serves 2. 25 minutes, 25 at the stove.

About 410 calories a serving, 24 g protein, 7 g carbohydrate, 31 g fat. From USDA figures for 100% of the ingredients; amounts are the recipe's.

1. Slice one medium onion thin. Heat one tablespoon of butter in a 10-inch nonstick skillet over medium heat and add the onion with a pinch of salt. Stir often until it softens and browns at the edges, about 10 minutes; scrape it to one side of the pan.10 min
2. While the onion cooks, crack four eggs into a bowl, add a pinch of salt and pepper, and whisk until the yolks and whites are blended. Shred the Swiss cheese wedge on the coarse side of a box grater.
3. Push the onion to the edge of the pan, add the remaining one tablespoon of butter to the center, and pour in the eggs once it foams. Stir gently with a spatula, scraping the bottom and sides of the pan as the eggs set, until they are mostly firm but still wet on top, about 2 minutes.2 min
4. Scatter the shredded cheese over the top and fold the omelet in half. Slide it onto a plate to finish cooking from residual heat while you plate the second serving.

Note Swap the onion for fresh herbs if you have chives or parsley. Leftovers keep a day covered; reheat gently over low heat. Serve with toast and a simple salad or leftover vegetables.

A half block of swiss cheese becomes supper in thirty minutes, baked into a skillet frittata with caramelized onions that turn sweet and mild. It's the kind of dish that tastes richer than its parts, and leftovers are fine cold the next day.

Serves 2. 35 minutes, 15 at the stove.

About 530 calories a serving, 34 g protein, 8 g carbohydrate, 41 g fat. From USDA figures for 83% of the ingredients; amounts are the recipe's.

1. Heat the broiler to high. Slice 1 large onion thin and melt 2 tablespoons butter in a 10-inch skillet over medium heat, then add the onion and 1/4 teaspoon salt. Cook for 12 minutes, stirring often, until the onion is soft and golden at the edges.12 min
2. While the onion cooks, whisk together 6 eggs with 1/4 teaspoon pepper and a pinch of salt, then grate 4 ounces swiss cheese into the eggs and stir until mixed.
3. Pour the egg mixture over the cooked onion in the skillet and stir gently. Cook without stirring for 2 minutes until the edges start to set.2 min
4. Transfer the skillet to the broiler and cook for 3 to 4 minutes, watching through the window, until the top is set and light gold. The center may jiggle slightly when you shake the pan, and that's right.4 min
5. Let the frittata rest for 2 minutes, then slide it onto a cutting board and cut into two wedges.

Note Swap the swiss for gruyere if you have it, or use any hard cheese from the shelf. The frittata keeps in the fridge for two days; eat it cold or warmed gently in a skillet. Serve with a green salad or a slice of bread to catch the eggs.

A few slices of melted swiss cheese set the tone for a fast, savory supper of eggs and onion. This shelf had almost nothing, so we build from staples and let the cheese carry the flavour. Serve with bread if you have it.

Serves 2. 15 minutes, 12 at the stove.

About 410 calories a serving, 22 g protein, 7 g carbohydrate, 33 g fat. From USDA figures for 100% of the ingredients; amounts are the recipe's.

1. Heat 2 tablespoons of oil in a large skillet over medium heat and slice 1 onion into thin half-moons. Cook the onion, stirring occasionally, until it starts to soften and turn golden, about 5 minutes.5 min
2. Crack 4 eggs into a bowl, add a pinch of salt and pepper, and whisk together until combined. While the onion cooks, tear a few slices of swiss cheese into smaller pieces.
3. Push the onion to the edges of the skillet and pour the eggs into the centre. Let them sit undisturbed for about 20 seconds, then gently stir and fold the eggs as they set. Scatter the cheese over the eggs.3 min
4. Continue cooking and stirring gently until the eggs are set but still tender, about 2 minutes more. Taste and adjust salt and pepper. Slide onto plates and serve right away.2 min

Note Swap diced ham or smoked salmon for onion if you have it. Leftovers keep in the fridge for a day; reheat gently. Serve with toast or roasted vegetables on the side.