## Step 1: Define the symbolic representation of the variables
The variables are 'green beans', 'bananas', 'chicken thighs', and 'milkshakes', which can be represented symbolically as $x_0$, $x_1$, $x_2$, and $x_3$ respectively.

## Step 2: Convert the objective function into symbolic notation
The objective function to maximize is $4x_0 + 2x_1 + 4x_2 + 8x_3$.

## Step 3: List the constraints in symbolic notation
The constraints are:
- $18x_0 + 19x_1 + 3x_2 + 18x_3 \leq 193$ (total iron)
- $17x_0 + 11x_1 + 19x_2 + 4x_3 \leq 237$ (total tastiness)
- $3x_2 + 18x_3 \geq 34$ (iron from chicken thighs and milkshakes)
- $19x_1 + 18x_3 \geq 46$ (iron from bananas and milkshakes)
- $18x_0 + 3x_2 \geq 41$ (iron from green beans and chicken thighs)
- $17x_0 + 4x_3 \geq 30$ (tastiness from green beans and milkshakes)
- $17x_0 + 11x_1 \geq 44$ (tastiness from green beans and bananas)
- $17x_0 + 11x_1 + 4x_3 \geq 48$ (tastiness from green beans, bananas, and milkshakes)
- $11x_1 + 19x_2 + 4x_3 \geq 48$ (tastiness from bananas, chicken thighs, and milkshakes)
- $17x_0 + 19x_2 + 4x_3 \geq 48$ (tastiness from green beans, chicken thighs, and milkshakes)
- $17x_0 + 11x_1 + 4x_3 \geq 59$ (tastiness from green beans, bananas, and milkshakes)
- $11x_1 + 19x_2 + 4x_3 \geq 59$ (tastiness from bananas, chicken thighs, and milkshakes)
- $17x_0 + 19x_2 + 4x_3 \geq 59$ (tastiness from green beans, chicken thighs, and milkshakes)
- $17x_0 + 11x_1 + 4x_3 \geq 49$ (tastiness from green beans, bananas, and milkshakes)
- $11x_1 + 19x_2 + 4x_3 \geq 49$ (tastiness from bananas, chicken thighs, and milkshakes)
- $17x_0 + 19x_2 + 4x_3 \geq 49$ (tastiness from green beans, chicken thighs, and milkshakes)
- $18x_0 + 19x_1 \leq 148$ (iron from green beans and bananas)
- $19x_1 + 18x_3 \leq 97$ (iron from bananas and milkshakes)
- $3x_2 + 18x_3 \leq 131$ (iron from chicken thighs and milkshakes)
- $19x_1 + 3x_2 \leq 81$ (iron from bananas and chicken thighs)
- $18x_0 + 3x_2 \leq 66$ (iron from green beans and chicken thighs)
- $18x_0 + 19x_1 + 3x_2 + 18x_3 \leq 66$ (total iron from all)
- $19x_2 + 4x_3 \leq 125$ (tastiness from chicken thighs and milkshakes)
- $17x_0 + 4x_3 \leq 170$ (tastiness from green beans and milkshakes)
- $11x_1 + 4x_3 \leq 125$ (tastiness from bananas and milkshakes)
- $17x_0 + 11x_1 + 19x_2 \leq 228$ (tastiness from green beans, bananas, and chicken thighs)
- $17x_0 + 11x_1 + 19x_2 + 4x_3 \leq 228$ (tastiness from all)

## 4: Create the symbolic representation of the problem
```json
{
    'sym_variables': [
        ('x0', 'green beans'),
        ('x1', 'bananas'),
        ('x2', 'chicken thighs'),
        ('x3', 'milkshakes')
    ],
    'objective_function': '4*x0 + 2*x1 + 4*x2 + 8*x3',
    'constraints': [
        '18*x0 + 19*x1 + 3*x2 + 18*x3 <= 193',
        '17*x0 + 11*x1 + 19*x2 + 4*x3 <= 237',
        '3*x2 + 18*x3 >= 34',
        '19*x1 + 18*x3 >= 46',
        '18*x0 + 3*x2 >= 41',
        '17*x0 + 4*x3 >= 30',
        '17*x0 + 11*x1 >= 44',
        '17*x0 + 11*x1 + 4*x3 >= 48',
        '11*x1 + 19*x2 + 4*x3 >= 48',
        '17*x0 + 19*x2 + 4*x3 >= 48',
        '17*x0 + 11*x1 + 4*x3 >= 59',
        '11*x1 + 19*x2 + 4*x3 >= 59',
        '17*x0 + 19*x2 + 4*x3 >= 59',
        '17*x0 + 11*x1 + 4*x3 >= 49',
        '11*x1 + 19*x2 + 4*x3 >= 49',
        '17*x0 + 19*x2 + 4*x3 >= 49',
        '18*x0 + 19*x1 <= 148',
        '19*x1 + 18*x3 <= 97',
        '3*x2 + 18*x3 <= 131',
        '19*x1 + 3*x2 <= 81',
        '18*x0 + 3*x2 <= 66',
        '18*x0 + 19*x1 + 3*x2 + 18*x3 <= 66',
        '19*x2 + 4*x3 <= 125',
        '17*x0 + 4*x3 <= 170',
        '11*x1 + 4*x3 <= 125',
        '17*x0 + 11*x1 + 19*x2 <= 228',
        '17*x0 + 11*x1 + 19*x2 + 4*x3 <= 228'
    ]
}
```

## 5: Implement the optimization problem using Gurobi
```python
import gurobi

# Create a new model
m = gurobi.Model()

# Define the variables
x0 = m.addVar(name="green_beans", lb=0)
x1 = m.addVar(name="bananas", lb=0)
x2 = m.addVar(name="chicken_thighs", lb=0)
x3 = m.addVar(name="milkshakes", lb=0)

# Objective function
m.setObjective(4*x0 + 2*x1 + 4*x2 + 8*x3, gurobi.GRB.MAXIMIZE)

# Constraints
m.addConstr(18*x0 + 19*x1 + 3*x2 + 18*x3 <= 193)
m.addConstr(17*x0 + 11*x1 + 19*x2 + 4*x3 <= 237)
m.addConstr(3*x2 + 18*x3 >= 34)
m.addConstr(19*x1 + 18*x3 >= 46)
m.addConstr(18*x0 + 3*x2 >= 41)
m.addConstr(17*x0 + 4*x3 >= 30)
m.addConstr(17*x0 + 11*x1 >= 44)
m.addConstr(17*x0 + 11*x1 + 4*x3 >= 48)
m.addConstr(11*x1 + 19*x2 + 4*x3 >= 48)
m.addConstr(17*x0 + 19*x2 + 4*x3 >= 48)
m.addConstr(17*x0 + 11*x1 + 4*x3 >= 59)
m.addConstr(11*x1 + 19*x2 + 4*x3 >= 59)
m.addConstr(17*x0 + 19*x2 + 4*x3 >= 59)
m.addConstr(17*x0 + 11*x1 + 4*x3 >= 49)
m.addConstr(11*x1 + 19*x2 + 4*x3 >= 49)
m.addConstr(17*x0 + 19*x2 + 4*x3 >= 49)
m.addConstr(18*x0 + 19*x1 <= 148)
m.addConstr(19*x1 + 18*x3 <= 97)
m.addConstr(3*x2 + 18*x3 <= 131)
m.addConstr(19*x1 + 3*x2 <= 81)
m.addConstr(18*x0 + 3*x2 <= 66)
m.addConstr(18*x0 + 19*x1 + 3*x2 + 18*x3 <= 66)
m.addConstr(19*x2 + 4*x3 <= 125)
m.addConstr(17*x0 + 4*x3 <= 170)
m.addConstr(11*x1 + 4*x3 <= 125)
m.addConstr(17*x0 + 11*x1 + 19*x2 <= 228)
m.addConstr(17*x0 + 11*x1 + 19*x2 + 4*x3 <= 228)

# Solve the model
m.optimize()

# Print the solution
if m.status == gurobi.GRB.OPTIMAL:
    print("Objective: ", m.objVal)
    print("Green beans: ", x0.varValue)
    print("Bananas: ", x1.varValue)
    print("Chicken thighs: ", x2.varValue)
    print("Milkshakes: ", x3.varValue)
else:
    print("The model is infeasible")
```